# URL String Parsing

> **NOTE**<br>
> The initial APIs of this module are supported since API version 7. Newly added APIs will be marked with a superscript to indicate their earliest API version.


## Modules to Import

```
import Url from '@ohos.url' 
```

## URLSearchParams


### constructor

constructor(init?: string[][] | Record&lt;string, string&gt; | string | URLSearchParams)

Creates a **URLSearchParams** instance.

**System capability**: SystemCapability.Utils.Lang

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| init | string[][]&nbsp;\|&nbsp;Record&lt;string,&nbsp;string&gt;&nbsp;\|&nbsp;string&nbsp;\|&nbsp;URLSearchParams | No| Input parameter objects, which include the following:<br>- **string[][]**: two-dimensional string array<br>-&nbsp;**Record&lt;string,&nbsp;string&gt;**: list of objects<br>- **string**: string<br>- **URLSearchParams**: object |

**Example**

```js
var objectParams = new Url.URLSearchParams([ ['user1', 'abc1'], ['query2', 'first2'], ['query3', 'second3'] ]);
var objectParams1 = new Url.URLSearchParams({"fod" : 1 , "bard" : 2});
var objectParams2 = new Url.URLSearchParams('?fod=1&bard=2');
var urlObject = new Url.URL('https://developer.mozilla.org/?fod=1&bard=2');
var params = new Url.URLSearchParams(urlObject.search);
```


### append

append(name: string, value: string): void

Appends a key-value pair into the query string.

**System capability**: SystemCapability.Utils.Lang

**Parameters**

 | Name | Type | Mandatory | Description |
 | -------- | -------- | -------- | -------- |
 | name | string | Yes | Key of the key-value pair to append. |
 | value | string | Yes | Value of the key-value pair to append. |

**Example**

```js
let urlObject = new Url.URL('https://developer.exampleUrl/?fod=1&bard=2');
let paramsObject = new Url.URLSearchParams(urlObject.search.slice(1));
paramsObject.append('fod', 3);
```


### delete

delete(name: string): void

Deletes key-value pairs of the specified key.

**System capability**: SystemCapability.Utils.Lang

**Parameters**

 | Name | Type | Mandatory | Description |
 | -------- | -------- | -------- | -------- |
 | name | string | Yes | Key of the key-value pairs to delete. |

**Example**

```js
let urlObject = new Url.URL('https://developer.exampleUrl/?fod=1&bard=2');
let paramsobject = new Url.URLSearchParams(urlObject.search.slice(1));
paramsobject.delete('fod');
```


### getAll

getAll(name: string): string[]

Obtains all the key-value pairs based on the specified key.

**System capability**: SystemCapability.Utils.Lang

**Parameters**

 | Name | Type | Mandatory | Description |
 | -------- | -------- | -------- | -------- |
 | name | string | Yes | Key specified to obtain all key-value pairs. |

**Return value**

 | Type | Description |
 | -------- | -------- |
 | string[] | All key-value pairs matching the specified key. |

**Example**

```js
let urlObject = new Url.URL('https://developer.exampleUrl/?fod=1&bard=2');
let params = new Url.URLSearchParams(urlObject.search.slice(1));
params.append('fod', '3'); // Add a second value for the fod parameter.
console.log(params.getAll('fod').toString()) // Output ["1","3"].
```


### entries

entries(): IterableIterator<[string, string]>

Obtains an ES6 iterator. Each item of the iterator is a JavaScript array, and the first and second fields of each array are the key and value respectively.

**System capability**: SystemCapability.Utils.Lang

**Return value**

 | Type | Description |
 | -------- | -------- |
 | IterableIterator&lt;[string,&nbsp;string]&gt; | ES6 iterator. |

**Example**

```js
var searchParamsObject = new Url.URLSearchParams("keyName1=valueName1&keyName2=valueName2"); 
for (var pair of searchParamsObject .entries()) { // Show keyName/valueName pairs
    console.log(pair[0]+ ', '+ pair[1]);
}
```


### forEach

forEach(callbackfn: (value: string, key: string, searchParams: this) => void, thisArg?: Object): void

Traverses the key-value pairs in the **URLSearchParams** instance by using a callback.

**System capability**: SystemCapability.Utils.Lang

**Parameters**

 | Name | Type | Mandatory | Description |
 | -------- | -------- | -------- | -------- |
 | callbackfn | function | Yes | Callback invoked to traverse the key-value pairs in the **URLSearchParams** instance. |
 | thisArg | Object | No | Value to use when the callback is invoked. |

**Table 1** callbackfn parameter description

 | Name | Type | Mandatory | Description |
 | -------- | -------- | -------- | -------- |
 | value | string | Yes | Value that is currently traversed. |
 | key | string | Yes | Key that is currently traversed. |
 | searchParams | Object | Yes | Instance that invokes the **forEach** method. |

**Example**

```js
const myURLObject = new Url.URL('https://developer.exampleUrl/?fod=1&bard=2'); 
myURLObject.searchParams.forEach((value, name, searchParams) => {  
    console.log(name, value, myURLObject.searchParams === searchParams);
});
```


### get

get(name: string): string | null

Obtains the value of the first key-value pair based on the specified key.

**System capability**: SystemCapability.Utils.Lang

**Parameters**

 | Name | Type | Mandatory | Description |
 | -------- | -------- | -------- | -------- |
 | name | string | Yes | Key specified to obtain the value. |

**Return value**

 | Type | Description |
 | -------- | -------- |
 | string | Returns the value of the first key-value pair if obtained. |
 | null | Returns null if no value is obtained. |

**Example**

```js
var paramsOject = new Url.URLSearchParams(document.location.search.substring(1)); 
var name = paramsOject.get("name"); // is the string "Jonathan" 
var age = parseInt(paramsOject.get("age"), 10); // is the number 18
var address = paramsOject.get("address"); // null
```


### has

has(name: string): boolean

Checks whether a key has a value.

**System capability**: SystemCapability.Utils.Lang

**Parameters**

 | Name | Type | Mandatory | Description |
 | -------- | -------- | -------- | -------- |
 | name | string | Yes | Key specified to search for its value. |

**Return value**

 | Type | Description |
 | -------- | -------- |
 | boolean | Returns **true** if the value exists; returns **false** otherwise. |

**Example**

```js
let urlObject = new Url.URL('https://developer.exampleUrl/?fod=1&bard=2');
let paramsObject = new Url.URLSearchParams(urlObject.search.slice(1)); 
paramsObject.has('bard') === true;
```


### set

set(name: string, value: string): void

Sets the value for a key. If key-value pairs matching the specified key exist, the value of the first key-value pair will be set to the specified value and other key-value pairs will be deleted. Otherwise, the key-value pair will be appended to the query string.

**System capability**: SystemCapability.Utils.Lang

**Parameters**

 | Name | Type | Mandatory | Description |
 | -------- | -------- | -------- | -------- |
 | name | string | Yes | Key of the value to set. |
 | value | string | Yes | Value to set. |

**Example**

```js
let urlObject = new Url.URL('https://developer.exampleUrl/?fod=1&bard=2');
let paramsObject = new Url.URLSearchParams(urlObject.search.slice(1));
paramsObject.set('baz', 3); // Add a third parameter.
```


### sort

sort(): void

Sorts all key-value pairs contained in this object based on the Unicode code points of the keys and returns undefined.  This method uses a stable sorting algorithm, that is, the relative order between key-value pairs with equal keys is retained.

**System capability**: SystemCapability.Utils.Lang

**Example**

```js
var searchParamsObject = new Url.URLSearchParams("c=3&a=9&b=4&d=2"); // Create a test URLSearchParams object
searchParamsObject.sort(); // Sort the key/value pairs
console.log(searchParamsObject.toString()); // Display the sorted query string // Output a=9&b=2&c=3&d=4
```


### keys

keys(): IterableIterator&lt;string&gt;

Obtains an ES6 iterator that contains the keys of all the key-value pairs.

**System capability**: SystemCapability.Utils.Lang

**Return value**

 | Type | Description |
 | -------- | -------- |
 | IterableIterator&lt;string&gt; | ES6 iterator that contains the keys of all the key-value pairs. |

**Example**

```js
var searchParamsObject = new Url.URLSearchParams("key1=value1&key2=value2"); // Create a URLSearchParamsObject object for testing
for (var key of searchParamsObject .keys()) { // Output key-value pairs
    console.log(key);
}
```


### values

values(): IterableIterator&lt;string&gt;

Obtains an ES6 iterator that contains the values of all the key-value pairs.

**System capability**: SystemCapability.Utils.Lang

**Return value**

 | Type | Description |
 | -------- | -------- |
 | IterableIterator&lt;string&gt; | ES6 iterator that contains the values of all the key-value pairs. |

**Example**

```js
var searchParams = new Url.URLSearchParams("key1=value1&key2=value2"); // Create a URLSearchParamsObject object for testing
for (var value of searchParams.values()) { 
    console.log(value);
}
```


### [Symbol.iterator]

[Symbol.iterator]\(): IterableIterator&lt;[string, string]&gt;

Obtains an ES6 iterator. Each item of the iterator is a JavaScript array, and the first and second fields of each array are the key and value respectively.

**System capability**: SystemCapability.Utils.Lang

**Return value**

 | Type | Description |
 | -------- | -------- |
 | IterableIterator&lt;[string,&nbsp;string]&gt; | ES6 iterator. |

**Example**

```js
const paramsObject = new Url.URLSearchParams('fod=bay&edg=bap');
for (const [name, value] of paramsObject) { 
    console.log(name, value); 
} 
```


### tostring

toString(): string

Obtains search parameters that are serialized as a string and, if necessary, percent-encodes the characters in the string.

**System capability**: SystemCapability.Utils.Lang

**Return value**

 | Type | Description |
 | -------- | -------- |
 | string | String of serialized search parameters, which is percent-encoded if necessary. |

**Example**

```js
let url = new Url.URL('https://developer.exampleUrl/?fod=1&bard=2');
let params = new Url.URLSearchParams(url.search.slice(1)); 
params.append('fod', 3);
console.log(params.toString());
```


## URL

### Attributes

**System capability**: SystemCapability.Utils.Lang

| Name| Type| Readable| Writable| Description|
| -------- | -------- | -------- | -------- | -------- |
| hash | string | Yes| Yes| String that contains a harsh mark (#) followed by the fragment identifier of a URL.|
| host | string | Yes| Yes| Host information in a URL.|
| hostname | string | Yes| Yes| Hostname (without the port) in a URL.|
| href | string | Yes| Yes| String that contains the whole URL.|
| origin | string | Yes| No| Read-only string that contains the Unicode serialization of the origin of the represented URL.|
| password | string | Yes| Yes| Password in a URL.|
| pathname | string | Yes| Yes| Path in a URL.|
| port | string | Yes| Yes| Port in a URL.|
| protocol | string | Yes| Yes| Protocol in a URL.|
| search | string | Yes| Yes| Serialized query string in a URL.|
| searchParams | URLsearchParams | Yes| No| **URLSearchParams** object allowing access to the query parameters in a URL.|
| username | string | Yes| Yes| Username in a URL.|


### constructor

constructor(url: string, base?: string | URL)

Creates a URL.

**System capability**: SystemCapability.Utils.Lang

**Parameters**

 | Name | Type | Mandatory | Description |
 | -------- | -------- | -------- | -------- |
 | url | string | Yes | Input object. |
 | base | string&nbsp;\ |&nbsp;URL | No | Input parameter, which can be any of the following:<br>- **string**: string<br>- **URL**: string or object |

**Example**

```js
var mm = 'http://username:password@host:8080';
var a = new Url.URL("/", mm); // Output 'http://username:password@host:8080/';
var b = new Url.URL(mm); // Output 'http://username:password@host:8080/';
new Url.URL('path/path1', b); // Output 'http://username:password@host:8080/path/path1';
var c = new Url.URL('/path/path1', b);  // Output 'http://username:password@host:8080/path/path1'; 
new Url.URL('/path/path1', c); // Output 'http://username:password@host:8080/path/path1';
new Url.URL('/path/path1', a); // Output 'http://username:password@host:8080/path/path1';
new Url.URL('/path/path1', "https://www.exampleUrl/fr-FR/toto"); // Output https://www.exampleUrl/path/path1
new Url.URL('/path/path1', ''); // Raises a TypeError exception as '' is not a valid URL
new Url.URL('/path/path1'); // Raises a TypeError exception as '/path/path1' is not a valid URL
new Url.URL('http://www.shanxi.com', ); // Output http://www.shanxi.com/
new Url.URL('http://www.shanxi.com', b); // Output http://www.shanxi.com/
```


### tostring

toString(): string

Converts the parsed URL into a string.

**System capability**: SystemCapability.Utils.Lang

**Return value**

 | Type | Description |
 | -------- | -------- |
 | string | Website address in a serialized string. |

**Example**

```js
const url = new Url.URL('http://username:password@host:8080/directory/file?query=pppppp#qwer=da');
url.toString()
```


### toJSON

toJSON(): string

Converts the parsed URL into a JSON string.

**System capability**: SystemCapability.Utils.Lang

**Return value**

 | Type | Description |
 | -------- | -------- |
 | string | Website address in a serialized string. |

**Example**
```js
const url = new Url.URL('http://username:password@host:8080/directory/file?query=pppppp#qwer=da');
url.toJSON()
```