added docs

Signed-off-by: Nwusongqing <wusongqing@huawei.com>

en/application-dev/reference/apis/js-apis-arraylist.md

+# Linear Container ArrayList
+
+> ![icon-note.gif](public_sys-resources/icon-note.gif) **NOTE**
+> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
+
+## Modules to Import
+
+```
+import ArrayList from '@ohos.util.ArrayList'
+```
+
+## System Capabilities
+
+SystemCapability.Utils.Lang
+
+## ArrayList
+
+### Attributes
+
+| Name| Type| Readable| Writable| Description|
+| -------- | -------- | -------- | -------- | -------- |
+| length | number | Yes| No| Number of entries in an array list (called container later).|
+
+
+### constructor
+
+constructor()
+
+A constructor used to create an **ArrayList** instance.
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+```
+
+
+### add
+
+add(element: T): boolean
+
+Adds an entry at the end of this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| element | T | Yes| Entry to add.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the entry is added successfully; returns **false** otherwise.|
+
+**Example**
+
+  ```
+  let arrayList = new ArrayList();
+  let result = arrayList.add("a");
+  let result1 = arrayList.add(1);
+  let b = [1, 2, 3];
+  let result2 = arrayList.add(b);
+  let c = {name: "lala", age: "13"};
+  let result3 = arrayList.add(false);
+  ```
+
+### insert
+
+insert(element: T, index: number): void
+
+Inserts an entry at the specified position in this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| element | T | Yes| Entry to insert.|
+| index | number | Yes| Index of the position where the entry is to be inserted.|
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.insert("A", 0);
+arrayList.insert(0, 1);
+arrayList.insert(true, 2);
+```
+
+### has
+
+has(element: T): boolean
+
+Checks whether this container has the specified entry.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| element | T | Yes| Entry to check.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the specified entry is contained; returns **false** otherwise.|
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+let result = arrayList.has("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+arrayList.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+let result1 = arrayList.has("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+```
+
+### getIndexOf
+
+getIndexOf(element: T): number
+
+Obtains the index of the first occurrence of the specified entry in this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| element | T | Yes| Entry to query.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| number | Returns the position index if obtained; returns **-1** if the specified entry is not found.|
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.add(2);
+arrayList.add(4);
+arrayList.add(5);
+arrayList.add(2);
+arrayList.add(1);
+arrayList.add(2);
+arrayList.add(4);
+let result = arrayList.getIndexOf(2);
+```
+
+### getLastIndexOf
+
+getLastIndexOf(element: T): number
+
+Obtains the index of the last occurrence of the specified entry in this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| element | T | Yes| Entry to query.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| number | Returns the position index if obtained; returns **-1** if the specified entry is not found.|
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.add(2);
+arrayList.add(4);
+arrayList.add(5);
+arrayList.add(2);
+arrayList.add(1);
+arrayList.add(2);
+arrayList.add(4);
+let result = arrayList.getLastIndexOf(2);
+```
+
+### removeByIndex
+
+removeByIndex(index: number): T
+
+Removes an entry with the specified position from this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| index | number | Yes| Position index of the entry to remove.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| T | Entry removed.|
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.add(2);
+arrayList.add(4);
+arrayList.add(5);
+arrayList.add(2);
+arrayList.add(4);
+let result = arrayList.removeByIndex(2);
+```
+
+### remove
+
+remove(element: T): boolean
+
+Removes the first occurrence of the specified entry from this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| element | T | Yes| Entry to remove.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the entry is removed successfully; returns **false** otherwise.|
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.add(2);
+arrayList.add(4);
+arrayList.add(5);
+arrayList.add(4);
+let result = arrayList.remove(2);
+```
+
+### removeByRange
+
+removeByRange(fromIndex: number, toIndex: number): void
+
+Removes from this container all of the entries within a range, including the entry at the start position but not that at the end position.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| fromIndex | number | Yes| Index of the start position.|
+| toIndex | number | Yes| Index of the end position.|
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.add(2);
+arrayList.add(4);
+arrayList.add(5);
+arrayList.add(4);
+arrayList.removeByRange(2, 4);
+arrayList.removeByRange(4, 3);
+arrayList.removeByRange(2, 6);
+```
+
+### replaceAllElements
+replaceAllElements(callbackfn: (value: T, index?: number, arrlist?: ArrayList<T>) => T,
+thisArg?: Object): void
+
+Replaces all entries in this container with new entries, and returns the new ones.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| callbackfn | function | Yes| Callback invoked for the replacement.|
+| thisArg | Object | No| Value to use when the callback is invoked.|
+
+callbackfn
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | T | Yes| Value of the entry that is currently traversed.|
+| index | number | No| Position index of the entry that is currently traversed.|
+| arrlist | ArrayList<T> | No| Instance that invokes the **replaceAllElements** method.|
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.add(2);
+arrayList.add(4);
+arrayList.add(5);
+arrayList.add(4);
+arrayList.replaceAllElements((value, index) => {
+  return value = 2 * value;
+});
+arrayList.replaceAllElements((value, index) => {
+  return value = value - 2;
+});
+```
+
+### forEach
+forEach(callbackfn: (value: T, index?: number, arrlist?: ArrayList<T>) => void,
+thisArg?: Object): void
+
+Uses a callback to traverse the entries in this container and obtain their position indexes.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| callbackfn | function | Yes| Callback invoked to traverse the entries in the container.|
+| thisArg | Object | No| Value to use when the callback is invoked.|
+
+callbackfn
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | T | Yes| Value of the entry that is currently traversed.|
+| index | number | No| Position index of the entry that is currently traversed.|
+| arrlist | ArrayList<T> | No| Instance that invokes the **forEach** method.|
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.add(2);
+arrayList.add(4);
+arrayList.add(5);
+arrayList.add(4);
+arrayList.forEach((value, index) => {
+  console.log(value, index);
+});
+```
+
+### sort
+sort(comparator?: (firstValue: T, secondValue: T) => number): void
+
+Sorts entries in this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| comparator | function | No| Callback invoked for sorting.|
+
+comparator
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| firstValue | T | Yes| Previous entry.|
+| secondValue | T | Yes| Next entry.|
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.add(2);
+arrayList.add(4);
+arrayList.add(5);
+arrayList.add(4);
+arrayList.sort(a, (b => a - b));
+arrayList.sort(a, (b => b - a));
+arrayList.sort();
+```
+
+### subArrayList
+subArrayList(fromIndex: number, toIndex: number): ArrayList<T>
+
+Obtains entries within a range in this container, including the entry at the start position but not that at the end position, and returns these entries as a new **ArrayList** instance.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| fromIndex | number | Yes| Index of the start position.|
+| toIndex | number | Yes| Index of the end position.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| ArrayList<T> | New **ArrayList** instance obtained.|
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.add(2);
+arrayList.add(4);
+arrayList.add(5);
+arrayList.add(4);
+let result1 = arrayList.subArrayList(2, 4);
+let result2 = arrayList.subArrayList(4, 3);
+let result3 = arrayList.subArrayList(2, 6);
+```
+
+### clear
+clear(): void
+
+Clears this container and sets its length to **0**.
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.add(2);
+arrayList.add(4);
+arrayList.add(5);
+arrayList.add(4);
+arrayList.clear();
+```
+
+### clone
+clone(): ArrayList<T> 
+
+Clones this container and returns a copy. The modification to the copy does not affect the original instance.
+
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| ArrayList<T> | New **ArrayList** instance obtained.|
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.add(2);
+arrayList.add(4);
+arrayList.add(5);
+arrayList.add(4);
+let result = arrayList.clone();
+```
+
+### getCapacity
+getCapacity(): number
+
+Obtains the capacity of this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| number | Capacity obtained.|
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.add(2);
+arrayList.add(4);
+arrayList.add(5);
+arrayList.add(4);
+let result = arrayList.getCapacity();
+```
+
+### convertToArray
+convertToArray(): Array<T>
+
+Converts this container into an array.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| Array<T> | Array obtained.|
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.add(2);
+arrayList.add(4);
+arrayList.add(5);
+arrayList.add(4);
+let result = arrayList.convertToArray();
+```
+
+### isEmpty
+isEmpty(): boolean
+
+Checks whether this container is empty (contains no entry).
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the container is empty; returns **false** otherwise.|
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.add(2);
+arrayList.add(4);
+arrayList.add(5);
+arrayList.add(4);
+let result = arrayList.isEmpty();
+```
+
+### increaseCapacityTo
+increaseCapacityTo(newCapacity: number): void
+
+Increases the capacity of this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| newCapacity | number | Yes| New capacity.|
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.add(2);
+arrayList.add(4);
+arrayList.add(5);
+arrayList.add(4);
+arrayList.increaseCapacityTo(2);
+arrayList.increaseCapacityTo(8);
+```
+
+### trimToCurrentLength
+trimToCurrentLength(): void
+
+Trims the capacity of this container to its current length.
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.add(2);
+arrayList.add(4);
+arrayList.add(5);
+arrayList.add(4);
+arrayList.trimToCurrentLength();
+```
+
+### [Symbol.iterator]
+
+[Symbol.iterator]\(): IterableIterator<T>
+
+Obtains an iterator, each item of which is a JavaScript object.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| IterableIterator<T> | Iterator obtained.|
+
+**Example**
+
+```
+let arrayList = new ArrayList();
+arrayList.add(2);
+arrayList.add(4);
+arrayList.add(5);
+arrayList.add(4);
+
+// Method 1:
+for (let item of arrayList) { 
+  console.log(item); 
+} 
+
+// Method 2:
+let iter = arrayList[Symbol.iterator]();
+let temp = iter.next().value;
+while(temp != undefined) {
+  console.log(temp);
+  temp = iter.next().value;
+}
+```

en/application-dev/reference/apis/js-apis-deque.md

+# Linear Container Deque
+
+> ![icon-note.gif](public_sys-resources/icon-note.gif) **NOTE**
+> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
+
+
+## Modules to Import
+
+```
+import Deque from '@ohos.util.Deque'  
+```
+
+## System Capabilities
+
+SystemCapability.Utils.Lang
+
+## Deque
+
+### Attributes
+
+| Name| Type| Readable| Writable| Description|
+| -------- | -------- | -------- | -------- | -------- |
+| length | number | Yes| No| Number of entries in a double-ended queue (deque, called container later).|
+
+### constructor
+
+constructor()
+
+A constructor used to create a **Deque** instance.
+
+**Example**
+
+```
+let deque = new Deque();
+```
+
+### insertFront
+
+insertFront(element: T): void
+
+Inserts an entry at the front of this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| element | T | Yes| Entry to insert.|
+
+**Example**
+
+```
+let deque = new Deque;
+deque.insertFront("a");
+deque.insertFront(1);
+let b = [1, 2, 3];
+deque.insertFront(b);
+let c = {name : "lala", age : "13"};
+deque.insertFront(false);
+```
+
+### insertEnd
+
+insertEnd(element: T): void
+
+Inserts an entry at the end of this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| element | T | Yes| Entry to insert.|
+
+**Example**
+
+```
+let deque = new Deque;
+deque.insertEnd("a");
+deque.insertEnd(1);
+let b = [1, 2, 3];
+deque.insertEnd(b);
+let c = {name : "lala", age : "13"};
+deque.insertEnd(false);
+```
+
+### has
+
+has(element: T): boolean
+
+Checks whether this container has the specified entry.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| element | T | Yes| Entry to check.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the specified entry is contained; returns **false** otherwise.|
+
+**Example**
+
+```
+let deque = new Deque();
+let result = deque.has("Ahfbrgrbgnutfodgorrogorg");
+deque.insertFront("Ahfbrgrbgnutfodgorrogorg");
+let result1 = deque.has("Ahfbrgrbgnutfodgorrogorg");
+```
+
+### popFirst
+
+popFirst(): T
+
+Removes the first entry of this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| T | Entry removed.|
+
+**Example**
+
+```
+let deque = new Deque();
+deque.insertFront(2);
+deque.insertFront(4);
+deque.insertEnd(5);
+deque.insertFront(2);
+deque.insertFront(4);
+let result = deque.popFirst();
+```
+
+### popLast
+
+popLast(): T
+
+Removes the last entry of this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| T | Entry removed.|
+
+**Example**
+
+```
+let deque = new Deque();
+deque.insertFront(2);
+deque.insertEnd(4);
+deque.insertFront(5);
+deque.insertFront(2);
+deque.insertFront(4);
+deque.popLast();
+let result = deque.popLast();
+```
+
+### forEach
+forEach(callbackfn: (value: T, index?: number, deque?: Deque<T>) => void,
+thisArg?: Object): void
+
+Uses a callback to traverse the entries in this container and obtain their position indexes.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| callbackfn | function | Yes| Callback invoked to traverse the entries in the container.|
+| thisArg | Object | No| Value to use when the callback is invoked.|
+
+callbackfn
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | T | Yes| Value of the element that is currently traversed.|
+| index | number | No| Position index of the entry that is currently traversed.|
+| deque | Deque<T> | No| Instance that invokes the **forEach** method.|
+
+**Example**
+
+```
+let deque = new Deque();
+deque.insertFront(2);
+deque.insertEnd(4);
+deque.insertFront(5);
+deque.insertEnd(4);
+deque.forEach((value, index) => {
+  console.log(value, index);
+});
+```
+
+### getFirst
+
+getFirst(): T;
+
+Obtains the first entry of this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| T | Entry obtained.|
+
+**Example**
+
+```
+let deque = new Deque();
+deque.insertEnd(2);
+deque.insertEnd(4);
+deque.insertFront(5);
+deque.insertFront(4);
+let result = deque.getFirst();
+```
+
+### getLast
+
+getLast(): T
+
+Obtains the last entry of this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| T | Entry obtained.|
+
+**Example**
+
+```
+let deque = new Deque();
+deque.insertFront(2);
+deque.insertFront(4);
+deque.insertFront(5);
+deque.insertFront(4);
+let result = deque.getLast();
+```
+
+### [Symbol.iterator]
+
+[Symbol.iterator]\(): IterableIterator<T>
+
+
+Obtains an iterator, each item of which is a JavaScript object.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| IterableIterator<T> | Iterator obtained.|
+
+**Example**
+```
+let deque = new Deque();
+deque.insertFront(2);
+deque.insertFront(4);
+deque.insertFront(5);
+deque.insertFront(4);
+
+// Method 1:
+for (let item of deque) { 
+  console.log(item); 
+}
+
+// Method 2:
+let iter = deque[Symbol.iterator]();
+let temp = iter.next().value;
+while(temp != undefined) {
+  console.log(temp);
+  temp = iter.next().value;
+}
+```

en/application-dev/reference/apis/js-apis-hashset.md

+# Nonlinear Container HashSet
+
+> ![icon-note.gif](public_sys-resources/icon-note.gif) **NOTE**
+> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
+
+
+## Modules to Import
+
+```
+import HashSet from '@ohos.util.HashSet';
+```
+
+## System Capabilities
+
+SystemCapability.Utils.Lang
+
+## HashSet
+
+
+### Attributes
+
+| Name| Type| Readable| Writable| Description|
+| -------- | -------- | -------- | -------- | -------- |
+| length | number | Yes| No| Number of entries in a hash set (called container later).|
+
+
+### constructor
+
+constructor()
+
+A constructor used to create a **HashSet** instance.
+
+**Example**
+
+```
+let hashSet = new HashSet();
+```
+
+
+### isEmpty
+
+isEmpty(): boolean
+
+Checks whether this container is empty (contains no entry).
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the container is empty; returns **false** otherwise.|
+
+**Example**
+
+```
+const hashSet = new HashSet();
+hashSet.isEmpty();
+```
+
+
+### has
+
+has(value: T): boolean
+
+Checks whether this container contains the specified entry.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | T | Yes| Entry to check.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the specified entry is contained; returns **false** otherwise.|
+
+**Example**
+
+```
+let hashSet = new HashSet();
+let result = hashSet.has("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+hashSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+let result1 = hashSet.has("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+```
+
+
+### add
+
+add(value: T): boolean
+
+Adds an entry to this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | T | Yes| Entry to add.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the entry is added successfully; returns **false** otherwise.|
+
+**Example**
+
+```
+let hashSet = new HashSet();
+let result = hashSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+```
+
+
+### remove
+
+remove(value: T): boolean
+
+Removes an entry from this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | T | Yes| Entry to remove.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the entry is removed successfully; returns **false** otherwise.|
+
+**Example**
+
+```
+let hashSet = new HashSet();
+hashSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+hashSet.add("sdfs");
+let result = hashSet.remove("sdfs");
+```
+
+
+### clear
+
+clear(): void
+
+Clears this container and sets its length to **0**.
+
+**Example**
+
+```
+let hashSet = new HashSet();
+hashSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+hashSet.add("sdfs");
+hashSet.clear();
+```
+
+
+### values
+
+values(): IterableIterator<T>
+
+Obtains an iterator that contains all the values in this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| IterableIterator<T> | Iterator obtained.|
+
+**Example**
+
+```
+let hashSet = new HashSet();
+hashSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+hashSet.add("sdfs");
+let iter = hashSet.values();
+let temp = iter.next().value;
+while(temp != undefined) {
+  console.log(temp);
+  temp = iter.next().value;
+} 
+```
+
+
+### forEach
+
+forEach(callbackfn: (value: T, key?: T, set?: HashSet<T>) => void, thisArg?: Object): void
+
+Uses a callback to traverse the entries in this container and obtain their position indexes.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| callbackfn | function | Yes| Callback invoked to traverse the entries in the container.|
+| thisArg | Object | No| Value to use when the callback is invoked.|
+
+callbackfn
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | T | Yes| Value of the entry that is currently traversed.|
+| key | T | No| Key of the entry that is currently traversed (same as **value**).|
+| set | HashSet<T> | No| Instance that invokes the **forEach** method.|
+
+**Example**
+
+```
+let hashSet = new HashSet();
+hashSet.add("sdfs");
+hashSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+hashSet.forEach((value, key) => {
+  console.log(value, key);
+});
+```
+
+
+### entries
+entries(): IterableIterator<[T, T]>
+
+Obtains an iterator that contains all the entries in this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| IterableIterator<[T, T]> | Iterator obtained.|
+
+**Example**
+
+```
+let hashSet = new HashSet();
+hashSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+hashSet.add("sdfs");
+let iter = hashSet.entries();
+let temp = iter.next().value;
+while(temp != undefined) {
+  console.log(temp[0]);
+  console.log(temp[1]);
+  temp = iter.next().value;
+}
+```
+
+
+### [Symbol.iterator]
+
+[Symbol.iterator]\(): IterableIterator&lt;T&gt;
+
+Obtains an iterator, each item of which is a JavaScript object.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| IterableIterator&lt;T&gt; | Iterator obtained.|
+
+**Example**
+
+```
+let hashSet = new HashSet();
+hashSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+hashSet.add("sdfs");
+
+// Method 1:
+for (let item of hashSet) { 
+  console.log("value: " + item);
+}
+
+// Method 2:
+let iter = hashSet[Symbol.iterator]();
+let temp = iter.next().value;
+while(temp != undefined) {
+  console.log(temp);
+  temp = iter.next().value;
+}
+```

en/application-dev/reference/apis/js-apis-lightweightset.md

+# Nonlinear Container LightWeightSet 
+
+> ![icon-note.gif](public_sys-resources/icon-note.gif) **NOTE**
+> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
+
+
+## Modules to Import
+
+```
+import LightWeightSet from '@ohos.util.LightWeightSet'  
+```
+
+## System Capabilities
+
+SystemCapability.Utils.Lang
+
+## LightWeightSet
+
+
+### Attributes
+
+| Name| Type| Readable| Writable| Description|
+| -------- | -------- | -------- | -------- | -------- |
+| length | number | Yes| No| Number of entries in a lightweight set (called container later).|
+
+
+### constructor
+
+constructor()
+
+A constructor used to create a **LightWeightSet** instance.
+
+**Example**
+
+```
+let lightWeightSet = new LightWeightSet();
+```
+
+
+### isEmpty
+
+isEmpty(): boolean
+
+Checks whether this container is empty.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the container is empty; returns **false** otherwise.|
+
+**Example**
+
+```
+const lightWeightSet = new LightWeightSet();
+let result = lightWeightSet.isEmpty();
+```
+
+### add
+
+add(obj: T): boolean
+
+Adds an entry to this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| obj | T | Yes| Entry to add.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the entry is added successfully; returns **false** otherwise.|
+
+**Example**
+
+```
+let lightWeightSet = new LightWeightSet();
+let result = lightWeightSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+```
+
+
+### addAll
+
+addAll(set: LightWeightSet<T>): boolean
+
+Adds all entries in a **LightWeightSet** instance to this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| set | LightWeightSet<T> | Yes| **LightWeightSet** instance whose entries are to be added to the current container.|
+
+**Example**
+
+```
+let lightWeightSet = new LightWeightSet();
+lightWeightSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+lightWeightSet.add("sdfs");
+let set = new LightWeightSet();
+set.add("sfage");
+let result = lightWeightSet.addAll(set);
+```
+
+
+### hasAll
+
+hasAll(set: LightWeightSet<T>): boolean
+
+Checks whether this container contains all entries of the specified **LightWeightSet** instance.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| set | LightWeightSet<T> | Yes| **LightWeightSet** instance to be used for comparison.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if all the entries in the specified **LightWeightSet** instance are contained; returns **false** otherwise.|
+
+**Example**
+
+```
+let lightWeightSet = new LightWeightSet();
+lightWeightSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+lightWeightSet.add("sdfs");
+let set = new LightWeightSet();
+set.add("sdfs");
+let result = lightWeightSet.hasAll(set);
+```
+
+
+### has
+
+has(key: T): boolean
+
+Checks whether this container has the specified key.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| key| T | Yes| Key to query.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the specified key is contained; returns **false** otherwise.|
+
+**Example**
+
+```
+let lightWeightSet = new LightWeightSet();
+let result = lightWeightSet.has(123);
+lightWeightSet.add(123);
+let result = lightWeightSet.has(123);
+```
+
+
+### equal
+
+equal(obj: Object): boolean
+
+Checks whether this container contains objects of the same type as the specified **obj**.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| obj | Object | Yes| Object to be used for comparison.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the container contains objects of the same type as the specified **obj**; returns **false** otherwise.|
+
+**Example**
+
+```
+let lightWeightSet = new LightWeightSet();
+lightWeightSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+lightWeightSet.add("sdfs");
+let obj = {"Ahfbrgrbgnutfodgorrogorgrogofdfdf", "sdfs"};
+let result = lightWeightSet.equal(obj);
+```
+
+
+### increaseCapacityTo
+
+increaseCapacityTo(minimumCapacity: number): void
+
+Increases the capacity of this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| minimumCapacity | number | Yes| Minimum number of entries to accommodate in the container.|
+
+**Example**
+
+```
+let lightWeightSet = new LightWeightSet();
+lightWeightSet.increaseCapacityTo(10);
+```
+
+
+### getIndexOf
+
+getIndexOf(key: T): number
+
+Obtains the position index of the entry with the specified key in this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| key | T | Yes| Key of the entry to query.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| number | Position index of the entry.|
+
+**Example**
+
+```
+let lightWeightSet = new LightWeightSet();
+lightWeightSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+lightWeightSet.add("sdfs");
+let result = lightWeightSet.getIndexOf("sdfs");
+```
+
+
+### remove
+
+remove(key: T): T
+
+Removes an entry of the specified key from this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| key | T | Yes| Key of the entry to remove.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| T | Value of the entry removed.|
+
+**Example**
+
+```
+let lightWeightSet = new LightWeightSet();
+lightWeightSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+lightWeightSet.add("sdfs");
+let result = lightWeightSet.remove("sdfs");
+```
+
+
+### removeAt
+
+removeAt(index: number): boolean
+
+Removes the entry at the specified position from this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| index | number | Yes| Position index of the entry to remove.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the entry is removed successfully; returns **false** otherwise.|
+
+**Example**
+
+```
+let lightWeightSet = new LightWeightSet();
+lightWeightSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+lightWeightSet.add("sdfs");
+let result = lightWeightSet.removeAt(1);
+```
+
+
+### getValueAt
+
+getValueAt(index: number): T
+
+Obtains the value of the entry at the specified position in this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| index | number | Yes| Position index of the entry.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| T | Value obtained.|
+
+**Parameters**
+
+```
+let lightWeightSet = new LightWeightSet();
+lightWeightSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+lightWeightSet.add("sdfs");
+let result = lightWeightSet.getValueAt(1);
+```
+
+
+### clear
+
+clear(): void
+
+Clears this container and sets its length to **0**.
+
+**Example**
+
+```
+let lightWeightSet = new LightWeightSet();
+lightWeightSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+lightWeightSet.add("sdfs");
+lightWeightSet.clear();
+```
+
+
+### toString
+
+toString(): String
+
+Obtains a string that contains all entries in this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| String | String obtained.|
+
+**Example**
+
+```
+let lightWeightSet = new LightWeightSet();
+lightWeightSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+lightWeightSet.add("sdfs");
+let result = lightWeightSet.toString();
+```
+
+
+### toArray
+
+toArray(): Array<T>
+
+Obtains an array that contains all objects in this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| Array<T> | Array obtained.|
+
+**Example**
+
+```
+let lightWeightSet = new LightWeightSet();
+lightWeightSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+lightWeightSet.add("sdfs");
+let result = lightWeightSet.toArray();
+```
+
+
+### values
+
+values(): IterableIterator<T>
+
+Obtains an iterator that contains all the values in this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| IterableIterator<T> | Iterator obtained.|
+
+**Example**
+
+```
+let lightWeightSet = new LightWeightSet();
+lightWeightSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+lightWeightSet.add("sdfs");
+let iter = lightWeightSet.values();
+let index = 0;
+while(index < lightWeightSet.length) {
+  console.log(JSON.stringify(iter.next().value));
+  index++;
+}
+```
+
+
+### forEach
+
+forEach(callbackfn: (value: T, key?: T, set?: LightWeightSet&lt;T&gt;) => void, thisArg?: Object): void
+
+Uses a callback to traverse the entries in this container and obtain their position indexes.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| callbackfn | function | Yes| Callback invoked to traverse the entries in the container.|
+| thisArg | Object | No| Value to use when the callback is invoked.|
+
+callbackfn
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | T | Yes| Value of the entry that is currently traversed.|
+| key | T | No| Key of the entry that is currently traversed (same as **value**).|
+| set | LightWeightSet&lt;T&gt; | No| Instance that invokes the **forEach** method.|
+
+**Example**
+
+```
+let lightWeightSet = new LightWeightSet();
+lightWeightSet.add("sdfs");
+lightWeightSet.add("dfsghsf");
+lightWeightSet.forEach((value, key) => {
+  console.log(value, key);
+});
+```
+
+
+### entries
+
+entries(): IterableIterator<[T, T]>
+
+Obtains an iterator that contains all the entries in this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| IterableIterator<[T, T]> | Iterator obtained.|
+
+**Example**
+
+```
+let lightWeightSet = new LightWeightSet();
+lightWeightSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+lightWeightSet.add("sdfs");
+let iter = lightWeightSet.entries();
+let index = 0;
+while(index < lightWeightSet.length) {
+  console.log(JSON.stringify(iter.next().value));
+  index++;
+}
+```
+
+
+### [Symbol.iterator]
+
+[Symbol.iterator]\(): IterableIterator&lt;T&gt;
+
+Obtains an iterator, each item of which is a JavaScript object.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| IterableIterator&lt;T&gt; | Iterator obtained.|
+
+**Example**
+
+```
+let lightWeightSet = new LightWeightSet();
+lightWeightSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+lightWeightSet.add("sdfs");
+
+// Method 1:
+for (let item of lightWeightSet) { 
+  console.log("value: " + item);
+}
+
+// Method 2:
+let iter = lightWeightSet[Symbol.iterator]();
+let temp = iter.next().value;
+while(temp != undefined) {
+  console.log(temp);
+  temp = iter.next().value;
+}
+```

en/application-dev/reference/apis/js-apis-list.md

+# Linear Container List
+
+> ![icon-note.gif](public_sys-resources/icon-note.gif) **NOTE**
+> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
+
+
+## Modules to Import
+
+```
+import List from '@ohos.util.List'  
+```
+
+## System Capabilities
+
+SystemCapability.Utils.Lang
+
+
+## List
+
+
+### Attributes
+
+| Name| Type| Readable| Writable| Description|
+| -------- | -------- | -------- | -------- | -------- |
+| length | number | Yes| No| Number of entries in a list (called container later).|
+
+
+### constructor
+
+constructor(head?: NodeObj<T>)
+
+A constructor used to create a **List** instance.
+
+**Parameters**
+
+| Name| Value Type | Readable| Description|
+| -------- | -------- | -------- | -------- |
+| head | NodeObj<T> | Yes| Node object, including **element** and **next**.|
+
+**Example**
+
+```
+let list = new List();
+```
+
+
+### add
+
+add(element: T): boolean
+
+Adds an entry at the end of this container.
+
+**Parameters**
+
+| Name| Value Type | Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| element | T | Yes| Element to add.|
+
+**Return value**
+
+| Value Type | Description|
+| -------- | -------- |
+| boolean | Returns **true** if the entry is added successfully; returns **false** otherwise.|
+
+**Example**
+
+```
+let list = new List;
+let result = list.add("a");
+let result1 = list.add(1);
+let b = [1, 2, 3];
+list.add(b);
+let c = {name : "lala", age : "13"};
+let result3 = list.add(false);
+```
+
+### insert
+
+insert(element: T, index: number): void
+
+Inserts an entry at the specified position in this container.
+
+**Parameters**
+
+| Name| Value Type | Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| element | T | Yes| Element to insert.|
+| index | number | Yes| Index of the position where the entry is to be inserted.|
+
+**Example**
+
+```
+let list = new List();
+list.insert("A", 0);
+list.insert(0, 1);
+list.insert(true, 2);
+```
+
+### has
+
+has(element: T): boolean
+
+Checks whether this container has the specified entry.
+
+**Parameters**
+
+| Name| Value Type | Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| element | T | Yes| Entry to query.|
+
+**Return value**
+
+| Value Type | Description|
+| -------- | -------- |
+| boolean | Returns **true** if the specified entry is contained; returns **false** otherwise.|
+
+**Example**
+
+```
+let list = new List();
+let result = list.has("Ahfbrgrbgnutfodgorrogorg");
+list.add("Ahfbrgrbgnutfodgorrogorg");
+let result1 = list.has("Ahfbrgrbgnutfodgorrogorg");
+```
+
+### get
+
+get(index: number): T
+
+Obtains the entry at the specified position in this container.
+
+**Parameters**
+
+| Name| Value Type | Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| index | number | Yes| Position index of the entry to obtain.|
+
+**Return value**
+
+| Value Type | Description|
+| -------- | -------- |
+| T | Entry obtained.|
+
+**Example**
+
+```
+let list = new List();
+list.add(2);
+list.add(4);
+list.add(5);
+list.add(2);
+list.add(1);
+list.add(2);
+list.add(4);
+let result = list.get(2);
+```
+
+### getLastIndexOf
+
+getLastIndexOf(element: T): number
+
+Obtains the index of the last occurrence of the specified entry in this container.
+
+**Parameters**
+
+| Name| Value Type | Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| element | T | Yes| Entry to query.|
+
+**Return value**
+
+| Value Type | Description|
+| -------- | -------- |
+| number | Returns the position index if obtained; returns **-1** if the specified entry is not found.|
+
+**Example**
+
+```
+let list = new List();
+list.add(2);
+list.add(4);
+list.add(5);
+list.add(2);
+list.add(1);
+list.add(2);
+list.add(4);
+let result = list.getLastIndexOf(2);
+```
+
+### getIndexOf
+
+getIndexOf(element: T): number
+
+Obtains the index of the first occurrence of the specified entry in this container.
+
+**Parameters**
+
+| Name| Value Type | Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| element | T | Yes| Entry to query.|
+
+**Return value**
+
+| Value Type | Description|
+| -------- | -------- |
+| number | Returns the position index if obtained; returns **-1** if the specified entry is not found.|
+
+**Example**
+
+```
+let list = new List();
+list.add(2);
+list.add(4);
+list.add(5);
+list.add(2);
+list.add(1);
+list.add(2);
+list.add(4);
+list.getIndexOf(2);
+let result = list.getIndexOf(2);
+```
+
+### equal
+
+equal(obj: Object): boolean
+
+Compares whether a specified object is equal to this container.
+
+**Parameters**
+
+| Name| Value Type | Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| obj | Object | Yes| Object used for comparison.|
+
+**Return value**
+
+| Value Type | Description|
+| -------- | -------- |
+| boolean | Returns **true** if the two are equal; returns **false** otherwise.|
+
+**Example**
+
+```
+let list = new List();
+list.add(2);
+list.add(4);
+list.add(5);
+list.add(2);
+let obj1 = new List();
+obj1.add(2);
+obj1.add(4);
+obj1.add(5);
+list.equal(obj1);
+let obj2 = {name : "lala", age : "13"};
+let result = list.equal(obj2);
+```
+
+### removeByIndex
+
+removeByIndex(index: number): T
+
+Removes an entry at the specified position from this container.
+
+**Parameters**
+
+| Name| Value Type | Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| index | number | Yes| Position index of the entry to remove.|
+
+**Return value**
+
+| Value Type | Description|
+| -------- | -------- |
+| T | Entry removed.|
+
+**Example**
+
+```
+let list = new List();
+list.add(2);
+list.add(4);
+list.add(5);
+list.add(2);
+list.add(4);
+let result = list.removeByIndex(2);
+```
+
+### remove
+
+remove(element: T): boolean
+
+Removes the first occurrence of the specified entry from this container.
+
+**Parameters**
+
+| Name| Value Type | Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| element | T | Yes| Entry to remove.|
+
+**Return value**
+
+| Value Type | Description|
+| -------- | -------- |
+| boolean | Returns **true** if the entry is removed successfully; returns **false** otherwise.|
+
+**Example**
+
+```
+let list = new List();
+list.add(2);
+list.add(4);
+list.add(5);
+list.add(4);
+let result = list.remove(2);
+```
+
+### replaceAllElements
+replaceAllElements(callbackfn: (value: T, index?: number, list?: List<T>) => T,
+thisArg?: Object): void
+
+Replaces all entries in this container with new entries, and returns the new ones.
+
+**Parameters**
+
+| Name| Value Type | Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| callbackfn | function | Yes| Callback invoked for the replacement.|
+| thisArg | Object | No| Value to use when the callback is invoked.|
+
+callbackfn
+
+| Name| Value Type | Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | T | Yes| Value of the entry that is currently traversed.|
+| index | number | No| Position index of the entry that is currently traversed.|
+| list | List<T> | No| Instance that invokes the **replaceAllElements** method.|
+
+**Example**
+
+```
+let list = new List();
+list.add(2);
+list.add(4);
+list.add(5);
+list.add(4);
+list.replaceAllElements((value, index) => {
+  return value = 2 * value;
+});
+list.replaceAllElements((value, index) => {
+  return value = value - 2;
+});
+```
+
+### forEach
+forEach(callbackfn: (value: T, index?: number, List?: List<T>) => void,
+thisArg?: Object): void
+
+Uses a callback to traverse the entries in this container and obtain their position indexes.
+
+**Parameters**
+
+| Name| Value Type | Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| callbackfn | function | Yes| Callback invoked to traverse the entries in the container.|
+| thisArg | Object | No| Value to use when the callback is invoked.|
+
+callbackfn
+
+| Name| Value Type | Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | T | Yes| Value of the entry that is currently traversed.|
+| index | number | No| Position index of the entry that is currently traversed.|
+| List | List<T> | No| Instance that invokes the **forEach** method.|
+
+**Example**
+
+```
+let list = new List();
+list.add(2);
+list.add(4);
+list.add(5);
+list.add(4);
+list.forEach((value, index) => {
+  console.log(value, index);
+});
+
+```
+
+### sort
+sort(comparator: (firstValue: T, secondValue: T) => number): void
+
+Sorts entries in this container.
+
+**Parameters**
+
+| Name| Value Type | Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| comparator | function | Yes| Callback invoked for sorting.|
+
+comparator
+
+| Name| Value Type | Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| firstValue | T | Yes| Previous entry.|
+| secondValue | T | Yes| Next entry.|
+
+**Example**
+
+```
+let list = new List();
+list.add(2);
+list.add(4);
+list.add(5);
+list.add(4);
+list.sort(a, (b => a - b));
+list.sort(a, (b => b - a));
+```
+
+### getSubList
+getSubList(fromIndex: number, toIndex: number): List<T>
+
+Obtains entries within a range in this container, including the entry at the start position but not that at the end position, and returns these entries as a new **List** instance.
+
+**Parameters**
+
+| Name| Value Type | Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| fromIndex | number | Yes| Index of the start position.|
+| toIndex | number | Yes| Index of the end position.|
+
+**Return value**
+
+| Value Type | Description|
+| -------- | -------- |
+| List<T> | New **List** instance obtained.|
+
+**Example**
+
+```
+let list = new List();
+list.add(2);
+list.add(4);
+list.add(5);
+list.add(4);
+let result = list.subList(2, 4);
+let result1 = list.subList(4, 3);
+let result2 = list.subList(2, 6);
+```
+
+### clear
+clear(): void
+
+Clears this container and sets its length to **0**.
+
+**Example**
+
+```
+let list = new List();
+list.add(2);
+list.add(4);
+list.add(5);
+list.add(4);
+list.clear();
+```
+
+### set
+set(index: number, element: T): T
+Replaces an entry at the specified position in this container with a given entry.
+
+**Parameters**
+
+| Name| Value Type | Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| index | number | Yes| Position index of the entry to replace.|
+| element | T | Yes| Entry to be used for replacement.|
+
+**Return value**
+
+| Value Type | Description|
+| -------- | -------- |
+| T | New entry.|
+
+**Example**
+
+```
+let list = new List();
+list.add(2);
+list.add(4);
+list.add(5);
+list.add(4);
+list.set(2, "b");
+
+```
+
+### convertToArray
+convertToArray(): Array<T>
+
+Converts this container into an array.
+
+**Return value**
+
+| Value Type | Description|
+| -------- | -------- |
+| Array<T> | Array obtained.|
+
+**Example**
+
+```
+let list = new List();
+list.add(2);
+list.add(4);
+list.add(5);
+list.add(4);
+let result = list.convertToArray();
+```
+
+### isEmpty
+isEmpty(): boolean
+
+Checks whether this container is empty (contains no entry).
+
+**Return value**
+
+| Value Type | Description|
+| -------- | -------- |
+| boolean | Returns **true** if the container is empty; returns **false** otherwise.|
+
+**Example**
+
+```
+let list = new List();
+list.add(2);
+list.add(4);
+list.add(5);
+list.add(4);
+let result = list.isEmpty();
+```
+
+### getFirst
+
+getFirst(): T
+
+Obtains the first entry in this container.
+
+**Return value**
+
+| Value Type | Description|
+| -------- | -------- |
+| T | The first entry obtained.|
+
+**Example**
+
+```
+let list = new Vector();
+list.add(2);
+list.add(4);
+list.add(5);
+list.add(4);
+let result = list.getFirst();
+```
+
+### getLast
+
+getLast(): T
+
+Obtains the last entry in this container.
+
+**Return value**
+
+| Value Type | Description|
+| -------- | -------- |
+| T | The last entry obtained.|
+
+**Example**
+
+```
+let list = new Vector();
+list.add(2);
+list.add(4);
+list.add(5);
+list.add(4);
+let result = list.getLast();
+```
+
+### [Symbol.iterator]
+
+[Symbol.iterator]\(): IterableIterator<T>;
+
+
+Obtains an iterator, each item of which is a JavaScript object.
+
+**Return value**
+
+| Value Type | Description|
+| -------- | -------- |
+| IterableIterator<T> | Iterator obtained.|
+
+**Example**
+
+```
+let list = new List();
+list.add(2);
+list.add(4);
+list.add(5);
+list.add(4);
+
+// Method 1:
+for (let item of list) { 
+  console.log(item); 
+}
+
+// Method 2:
+let iter = list[Symbol.iterator]();
+let temp = iter.next().value;
+while(temp != undefined) {
+  console.log(temp);
+  temp = iter.next().value;
+}
+```

en/application-dev/reference/apis/js-apis-queue.md

+# Linear Container Queue
+
+> ![icon-note.gif](public_sys-resources/icon-note.gif) **NOTE**
+> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
+
+
+## Modules to Import
+
+```
+import Queue from '@ohos.util.Queue'  
+```
+
+## System Capabilities
+
+SystemCapability.Utils.Lang
+
+
+## Queue
+
+
+### Attributes
+
+| Name| Type| Readable| Writable| Description|
+| -------- | -------- | -------- | -------- | -------- |
+| length | number | Yes| No| Number of entries in a queue (called container later).|
+
+
+### constructor
+
+constructor()
+
+A constructor used to create a **Queue** instance.
+
+**Example**
+
+```
+let queue = new Queue();
+```
+
+
+### add
+
+add(element: T): boolean
+
+Adds an entry at the end of this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| element | T | Yes| Entry to add.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the entry is added successfully; returns **false** otherwise.|
+
+**Example**
+
+```
+let queue = new Queue();
+let result = queue.add("a");
+let result1 = queue.add(1);
+queue.add(1);
+let b = [1, 2, 3];
+queue.add(b);
+let c = {name : "lala", age : "13"};
+let result3 = queue.add(c);
+```
+
+### pop
+
+pop(): T
+
+Removes the first entry from this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| T | Entry removed.|
+
+**Example**
+
+```
+let queue = new Queue();
+queue.add(2);
+queue.add(4);
+queue.add(5);
+queue.add(2);
+queue.add(4);
+let result = queue.pop();
+```
+
+### getFirst
+
+getFirst(): T
+
+Obtains the first entry of this container.
+
+**Parameters**
+
+| Type| Description|
+| -------- | -------- |
+| T | The first entry obtained.|
+
+**Example**
+
+```
+let queue = new Queue();
+queue.add(2);
+queue.add(4);
+queue.add(5);
+queue.add(2);
+let result = queue.getFirst();
+```
+
+### forEach
+forEach(callbackfn: (value: T, index?: number, Queue?: Queue<T>) => void,
+thisArg?: Object): void
+
+Uses a callback to traverse the entries in this container and obtain their position indexes.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| callbackfn | function | Yes| Callback invoked to traverse the entries in the container.|
+| thisArg | Object | No| Value to use when the callback is invoked.|
+
+callbackfn
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | T | Yes| Value of the entry that is currently traversed.|
+| index | number | No| Position index of the entry that is currently traversed.|
+| Queue | Queue<T> | No| Instance that invokes the **forEach** method.|
+
+**Example**
+
+```
+let queue = new Queue();
+queue.add(2);
+queue.add(4);
+queue.add(5);
+queue.add(4);
+queue.forEach((value, index) => {
+  console.log(value, index);
+});
+
+```
+
+### [Symbol.iterator]
+
+[Symbol.iterator]\(): IterableIterator<T>
+
+
+Obtains an iterator, each item of which is a JavaScript object.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| IterableIterator<T> | Iterator obtained.|
+
+**Example**
+```
+let queue = new Queue();
+queue.add(2);
+queue.add(4);
+queue.add(5);
+queue.add(4);
+
+// Method 1:
+for (let item of queue) { 
+  console.log(item); 
+}
+
+// Method 2:
+let iter = queue[Symbol.iterator]();
+let temp = iter.next().value;
+while(temp != undefined) {
+  console.log(temp);
+  temp = iter.next().value;
+}
+```

en/application-dev/reference/apis/js-apis-stack.md

+# Linear Container Stack
+
+> ![icon-note.gif](public_sys-resources/icon-note.gif) **NOTE**
+> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
+
+
+## Modules to Import
+
+```
+import Stack from '@ohos.util.Stack'  
+```
+
+## System Capabilities
+
+SystemCapability.Utils.Lang
+
+
+## Stack
+
+
+### Attributes
+
+| Name| Type| Readable| Writable| Description|
+| -------- | -------- | -------- | -------- | -------- |
+| length | number | Yes| No| Number of entries in a stack (called container later).|
+
+
+### constructor
+
+constructor()
+
+A constructor used to create a **Stack** instance.
+
+**Example**
+
+```
+let stack = new Stack();
+```
+
+
+### push
+
+push(item: T): T
+
+Adds an entry at the top of this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| item | T | Yes| Element to add.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| T | Element added.|
+
+**Example**
+
+```
+let stack = new Stack();
+let result = stack.push("a");
+let result1 = stack.push(1);
+let b = [1, 2, 3];
+stack.push(b);
+let c = {name : "lala", age : "13"};
+let result3 = stack.push(c);
+```
+
+### pop
+
+pop(): T
+
+Removes the top entry from this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| T | Entry removed.|
+
+**Example**
+
+```
+let stack = new Stack();
+stack.push(2);
+stack.push(4);
+stack.push(5);
+stack.push(2);
+stack.push(4);
+let result = stack.pop();
+```
+
+### peek
+
+peek(): T
+
+Obtains the top entry of this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| T | Entry obtained.|
+
+**Example**
+
+```
+let stack = new Stack();
+stack.push(2);
+stack.push(4);
+stack.push(5);
+stack.push(2);
+let result = stack.peek();
+```
+
+### locate
+
+locate(element: T): number
+
+Obtains the index of the first occurrence of the specified entry in this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| element | T | Yes| Entry to query.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| number | Returns the position index if obtained; returns **-1** if the specified entry is not found.|
+
+**Example**
+
+```
+let stack = new Stack();
+stack.push(2);
+stack.push(4);
+stack.push(5);
+stack.push(2);
+let result = stack.locate(2);
+```
+
+### forEach
+forEach(callbackfn: (value: T, index?: number, stack?: Stack<T>) => void,
+thisArg?: Object): void
+
+Uses a callback to traverse the entries in this container and obtain their position indexes.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| callbackfn | function | Yes| Callback invoked to traverse the entries in the container.|
+| thisArg | Object | No| Value to use when the callback is invoked.|
+
+callbackfn
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | T | Yes| Value of the entry that is currently traversed.|
+| index | number | No| Position index of the entry that is currently traversed.|
+| stack | Stack<T> | No| Instance that invokes the **forEach** method.|
+
+**Example**
+
+```
+let stack = new Stack();
+stack.push(2);
+stack.push(4);
+stack.push(5);
+stack.push(4);
+stack.forEach((value, index) => {
+ console.log(value, index);
+});
+```
+
+### isEmpty
+isEmpty(): boolean
+
+Checks whether this container is empty (contains no entries).
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the container is empty; returns **false** otherwise.|
+
+**Example**
+
+```
+let stack = new Stack();
+stack.push(2);
+stack.push(4);
+stack.push(5);
+stack.push(4);
+let result = stack.isEmpty();
+```
+
+### [Symbol.iterator]
+
+[Symbol.iterator]\(): IterableIterator<T>
+
+
+Obtains an iterator, each item of which is a JavaScript object.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| IterableIterator<T> | Iterator obtained.|
+
+**Example**
+```
+let stack = new Stack();
+stack.push(2);
+stack.push(4);
+stack.push(5);
+stack.push(4);
+
+// Method 1:
+for (let item of stack) { 
+  console.log(item); 
+}
+
+// Method 2:
+let iter = stack[Symbol.iterator]();
+let temp = iter.next().value;
+while(temp != undefined) {
+  console.log(temp);
+  temp = iter.next().value;
+}
+```

en/application-dev/reference/apis/js-apis-treemap.md

+# Nonlinear Container TreeMap 
+
+> ![icon-note.gif](public_sys-resources/icon-note.gif) **NOTE**
+> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
+
+
+## Modules to Import
+
+```
+import TreeMap from '@ohos.util.TreeMap'  
+```
+
+## System Capabilities
+
+SystemCapability.Utils.Lang
+
+## TreeMap
+
+
+### Attributes
+
+| Name| Type| Readable| Writable| Description|
+| -------- | -------- | -------- | -------- | -------- |
+| length | number | Yes| No| Number of entries in a tree map (called container later).|
+
+
+### constructor
+
+constructor(comparator?:(firstValue: K, secondValue: K) => boolean)
+
+A constructor used to create a **TreeMap** instance.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| comparator | function | No| Custom comparator.|
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+```
+
+
+### isEmpty
+
+isEmpty(): boolean;
+
+Checks whether this container is empty (contains no entry).
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the container is empty; returns **false** otherwise.|
+
+**Example**
+
+```
+const treeMap = new TreeMap();
+let result = treeMap.isEmpty();
+```
+
+
+### hasKey
+
+hasKey(key: K): boolean;
+
+Checks whether this container has the specified key.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| key | K | Yes| Key to query.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the specified key is contained; returns **false** otherwise.|
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+let result = treeMap.hasKey("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+treeMap.set("Ahfbrgrbgnutfodgorrogorgrogofdfdf", 123);
+let result1 = treeMap.hasKey("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+```
+
+
+### hasValue
+
+hasValue(value: V): boolean
+
+Checks whether this container has the specified value.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | V | Yes| Value to query.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the specified value is contained; returns **false** otherwise.|
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+let result = treeMap.hasValue(123);
+treeMap.set("Ahfbrgrbgnutfodgorrogorgrogofdfdf", 123);
+let result1 = treeMap.hasValue(123);
+```
+
+
+### get
+
+get(key: K): V
+
+Obtains the value of the specified key in this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| key | K | Yes| Key to query.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| V | Value of the key.|
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+treeMap.set("Ahfbrgrbgnutfodgorrogorgrogofdfdf", 123);
+treeMap.set("sdfs", 356);
+let result = treeMap.get("sdfs");
+```
+
+
+### getFirstKey
+
+getFirstKey(): K;
+
+Obtains the first key in this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| K | Key obtained.|
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+treeMap.set("Ahfbrgrbgnutfodgorrogorgrogofdfdf", 123);
+treeMap.set("sdfs", 356);
+let result = treeMap.getFirstKey();
+```
+
+
+### getLastKey
+
+getLastKey(): K;
+
+Obtains the last key in this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| K | Key obtained.|
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+treeMap.set("Ahfbrgrbgnutfodgorrogorgrogofdfdf", 123);
+treeMap.set("sdfs", 356);
+let result = treeMap.getLastKey();
+```
+
+
+### setAll
+
+setAll(map: TreeMap<K, V>): void
+
+Adds all entries in a **TreeMap** instance to this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| map | TreeMap<K, V> | Yes| **TreeMap** instance whose entries are to be added to the current container.|
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+treeMap.set("Ahfbrgrbgnutfodgorrogorgrogofdfdf", 123);
+treeMap.set("sdfs", 356);
+let map = new TreeMap();
+treeMap.setAll(map);
+```
+
+
+### set
+set(key: K, value: V): Object
+
+Adds an entry to this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| key | K | Yes| Key of the entry to add.|
+| value | V | Yes| Value of the entry to add.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| Object | Container that contains the new entry.|
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+treeMap.set("Ahfbrgrbgnutfodgorrogorgrogofdfdf", 123);
+```
+
+
+### remove
+
+remove(key: K): V;
+
+Removes the entry with the specified key from this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| key | K | Yes| Key of the entry to remove.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| V | Value of the entry removed.|
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+treeMap.set("Ahfbrgrbgnutfodgorrogorgrogofdfdf", 123);
+treeMap.set("sdfs", 356);
+treeMap.remove("sdfs");
+```
+
+
+### getLowerKey
+
+getLowerKey(key: K): K
+
+Obtains the key that is placed in front of the input key in this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| key | K | Yes| Input key.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| K | Key obtained.|
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+treeMap.set("Ahfbrgrbgnutfodgorrogorgrogofdfdf", 123);
+treeMap.set("sdfs", 356);
+treeMap.set("zdfgsd", 356);
+let result = treeMap.getLowerKey("sdfs");
+```
+
+
+### getHigherKey
+
+getHigherKey(key: K): K
+
+Obtains the key that is placed next to the input key in this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| key | K | Yes| Input key.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| K | Key obtained.|
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+treeMap.set("Ahfbrgrbgnutfodgorrogorgrogofdfdf", 123);
+treeMap.set("sdfs", 356);
+treeMap.set("zdfgsd", 356);
+let result = treeMap.getHigherKey("sdfs");
+```
+
+### replace
+replace(key: K, newValue: V): boolean
+
+Replaces an entry in this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| key | K | Yes| Key of the entry to replace.|
+| newValue | V | Yes| New value of the entry.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the entry is replaced successfully; returns **false** otherwise.|
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+treeMap.set("sdfs", 123);
+let result = treeMap.replace("sdfs", 357);
+```
+
+
+### clear
+
+clear(): void
+
+Clears this container and sets its length to **0**.
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+treeMap.set("Ahfbrgrbgnutfodgorrogorgrogofdfdf", 123);
+treeMap.set("sdfs", 356);
+treeMap.clear();
+```
+
+
+### keys
+
+keys(): IterableIterator&lt;K&gt;
+
+Obtains an iterator that contains all the keys in this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| IterableIterator&lt;K&gt; | Iterator obtained.|
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+treeMap.set("Ahfbrgrbgnutfodgorrogorgrogofdfdf", 123);
+treeMap.set("sdfs", 356);
+let iter = treeMap.keys();
+let temp = iter.next().value;
+while(temp != undefined) {
+  console.log(temp);
+  temp = iter.next().value;
+} 
+```
+
+
+### values
+
+values(): IterableIterator&lt;V&gt;
+
+Obtains an iterator that contains all the values in this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| IterableIterator&lt;V&gt; | Iterator obtained.|
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+treeMap.set("Ahfbrgrbgnutfodgorrogorgrogofdfdf", 123);
+treeMap.set("sdfs", 356);
+let iter = treeMap.values();
+let temp = iter.next().value;
+while(temp != undefined) {
+  console.log(temp);
+  temp = iter.next().value;
+}
+```
+
+
+### forEach
+
+forEach(callbackfn: (value: V, key?: K, map?: TreeMap<K, V>) => void, thisArg?: Object): void
+
+Uses a callback to traverse the entries in this container and obtain their position indexes.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| callbackfn | function | Yes| Callback invoked to traverse the entries in the container.|
+| thisArg | Object | No| Value to use when the callback is invoked.|
+
+callbackfn
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | V | Yes| Value of the entry that is currently traversed.|
+| key | K | Yes| Key of the entry that is currently traversed.|
+| map | TreeMap<K, V> | No| Instance that invokes the **forEach** method.|
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+treeMap.set("sdfs", 123);
+treeMap.set("dfsghsf", 357);
+treeMap.forEach((value, key) => {
+  console.log(value, key);
+});
+```
+
+
+### entries
+
+entries(): IterableIterator<[K, V]>
+
+Obtains an iterator that contains all the entries in this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| IterableIterator<[K, V]> | Iterator obtained.|
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+treeMap.set("Ahfbrgrbgnutfodgorrogorgrogofdfdf", 123);
+treeMap.set("sdfs", 356);
+let iter = treeMap.entries();
+let temp = iter.next().value;
+while(temp != undefined) {
+  console.log(temp[0]);
+  console.log(temp[1]);
+  temp = iter.next().value;
+}
+```
+
+
+### [Symbol.iterator]
+
+[Symbol.iterator]\(): IterableIterator&lt;[K, V]&gt;;
+
+
+Obtains an iterator, each item of which is a JavaScript object.
+
+**Return value**
+| Type| Description|
+| -------- | -------- |
+| IterableIterator<[K, V]> | Iterator obtained.|
+
+**Example**
+
+```
+let treeMap = new TreeMap();
+treeMap.set("Ahfbrgrbgnutfodgorrogorgrogofdfdf", 123);
+treeMap.set("sdfs", 356);
+
+// Method 1:
+for (let item of treeMap) { 
+  console.log("key: " + item[0]);
+  console.log("value: " + item[1]);
+}
+
+// Method 2:
+let iter = treeMap[Symbol.iterator]();
+let temp = iter.next().value;
+while(temp != undefined) {
+  console.log(temp[0]);
+  console.log(temp[1]);
+  temp = iter.next().value;
+}
+```

en/application-dev/reference/apis/js-apis-treeset.md

+# Nonlinear Container TreeSet 
+
+> ![icon-note.gif](public_sys-resources/icon-note.gif) **NOTE**
+> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
+
+
+## Modules to Import
+
+```
+import TreeSet from '@ohos.util.TreeSet'  
+```
+
+## System Capabilities
+
+SystemCapability.Utils.Lang
+
+## TreeSet
+
+
+### Attributes
+
+| Name| Type| Readable| Writable| Description|
+| -------- | -------- | -------- | -------- | -------- |
+| length | number | Yes| No| Number of entries in a tree set (called container later).|
+
+
+### constructor
+
+constructor(comparator?:(firstValue: T, secondValue: T) => boolean)
+
+A constructor used to create a **TreeSet** instance.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| comparator | function | No| Custom comparator.|
+
+**Example**
+
+```
+let treeSet = new TreeSet();
+```
+
+
+### isEmpty
+
+isEmpty(): boolean
+
+Checks whether this container is empty (contains no entry).
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the container is empty; returns **false** otherwise.|
+
+**Example**
+
+```
+const treeSet = new TreeSet();
+let result = treeSet.isEmpty();
+```
+
+
+### has
+
+has(value: T): boolean
+
+Checks whether this container has the specified value.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | T | Yes| Value to query.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the specified value is contained; returns **false** otherwise.|
+
+**Example**
+
+```
+let treeSet = new TreeSet();
+treeSet.has(123);
+treeSet.add(123);
+let result1 = treeSet.has(123);
+```
+
+
+### getFirstValue
+
+getFirstValue(): T
+
+Obtains the value of the first entry in this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| T | Value obtained.|
+
+**Example**
+
+```
+let treeSet = new TreeSet();
+treeSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+treeSet.add("sdfs");
+let result = treeSet.getFirstValue();
+```
+
+
+### getLastValue
+
+getLastValue(): T
+
+Obtains the value of the last entry in this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| T | Value obtained.|
+
+**Example**
+
+```
+let treeSet = new TreeSet();
+treeSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+treeSet.add("sdfs");
+let result = treeSet.getLastValue();
+```
+
+
+### add
+add(value: T): boolean
+
+Adds an entry to this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | T | Yes| Entry to add.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the entry is added successfully; returns **false** otherwise.|
+
+**Example**
+
+```
+let treeSet = new TreeSet();
+let result = treeSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+```
+
+
+### remove
+
+remove(value: T): boolean;
+
+Removes the entry with the specified key from this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | T | Yes| Key of the entry to remove.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| boolean | Returns **true** if the entry is removed successfully; returns **false** otherwise.|
+
+**Example**
+
+```
+let treeSet = new TreeSet();
+treeSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+treeSet.add("sdfs");
+let result = treeSet.remove("sdfs");
+```
+
+
+### getLowerValue
+
+getLowerValue(key: T): T
+
+Obtains the value that is placed in front of the input key in this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| key | T | Yes| Input key.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| T | Value obtained.|
+
+**Example**
+
+```
+let treeSet = new TreeSet();
+treeSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+treeSet.add("sdfs");
+treeSet.add("zdfgsd");
+let result = treeSet.getLowerValue("sdfs");
+```
+
+
+### getHigherValue
+
+getHigherValue(key: T): T
+
+Obtains the value that is placed next to the input key in this container.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| key | T | Yes| Input key.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| T | Value obtained.|
+
+**Example**
+
+```
+let treeSet = new TreeSet();
+treeSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+treeSet.add("sdfs");
+treeSet.add("zdfgsd");
+let result = treeSet.getHigherValue("sdfs");
+```
+
+
+### popFirst
+
+popFirst(): T
+
+Removes the first entry in this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| T | Entry removed.|
+
+**Return value**
+
+```
+let treeSet = new TreeSet();
+treeSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+treeSet.add("sdfs");
+let result = treeSet.popFirst();
+```
+
+
+### popLast
+
+popLast(): T
+
+Removes the last entry in this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| T | Entry removed.|
+
+**Return value**
+
+```
+let treeSet = new TreeSet();
+treeSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+treeSet.add("sdfs");
+let result = treeSet.popLast();
+```
+
+
+### clear
+
+clear(): void
+
+Clears this container and sets its length to **0**.
+
+**Example**
+
+```
+let treeSet = new TreeSet();
+treeSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+treeSet.add("sdfs");
+treeSet.clear();
+```
+
+
+### values
+
+values(): IterableIterator<T>
+
+Obtains an iterator that contains all the values in this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| IterableIterator<T> | Iterator obtained.|
+
+**Example**
+
+```
+let treeSet = new TreeSet();
+treeSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+treeSet.add("sdfs");
+let iter = treeSet.values();
+let temp = iter.next().value;
+while(temp != undefined) {
+  console.log(temp);
+  temp = iter.next().value;
+} 
+```
+
+
+### forEach
+
+forEach(callbackfn: (value: T, key?: T, set?: TreeSet<T>) => void, thisArg?: Object): void
+
+Uses a callback to traverse the entries in this container and obtain their position indexes.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| callbackfn | function | Yes| Callback invoked to traverse the entries in the container.|
+| thisArg | Object | No| Value to use when the callback is invoked.|
+
+callbackfn
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| value | T | Yes| Value of the entry that is currently traversed.|
+| key | T | No| Key of the entry that is currently traversed (same as **value**).|
+| set | TreeSet<T> | No| Instance that invokes the **forEach** method.|
+
+**Example**
+
+```
+let treeSet = new TreeSet();
+treeSet.add("sdfs");
+treeSet.add("dfsghsf");
+treeSet.forEach((value, key) => {
+  console.log(value, key)
+});
+```
+
+
+### entries
+
+entries(): IterableIterator<[T, T]>
+
+Obtains an iterator that contains all the entries in this container.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| IterableIterator<[T, T]> | Iterator obtained.|
+
+**Example**
+
+```
+let treeSet = new TreeSet();
+treeSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+treeSet.add("sdfs");
+let iter = treeSet.entries();
+let temp = iter.next().value;
+while(temp != undefined) {
+  console.log(temp[0]);
+  console.log(temp[1]);
+  temp = iter.next().value;
+}
+```
+
+
+### [Symbol.iterator]
+
+[Symbol.iterator]\(): IterableIterator&lt;T&gt;
+
+
+Obtains an iterator, each item of which is a JavaScript object.
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| IterableIterator&lt;T&gt; | Iterator obtained.|
+
+**Example**
+
+```
+let treeSet = new TreeSet();
+treeSet.add("Ahfbrgrbgnutfodgorrogorgrogofdfdf");
+treeSet.add("sdfs");
+  
+// Method 1:
+for (let item of treeSet) { 
+  console.log("value: " + item);
+}
+
+// Method 2:
+let iter = treeSet[Symbol.iterator]();
+let temp = iter.next().value;
+while(temp != undefined) {
+  console.log(temp);
+  temp = iter.next().value;
+}
+```