# @ohos.url (URL String Parsing)
> **NOTE**
>
> 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'
```
## URLParams9+
### constructor9+
constructor(init?: string[][] | Record<string, string> | string | URLSearchParams)
A constructor used to create a **URLParams** instance.
**System capability**: SystemCapability.Utils.Lang
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| init | string[][] \| Record<string, string> \| string \| URLSearchParams | No| Input parameter objects, which include the following:
- **string[][]**: two-dimensional string array
- **Record<string, string>**: list of objects
- **string**: string
- **URLSearchParams**: object|
**Example**
```js
let objectParams = new Url.URLParams([ ['user1', 'abc1'], ['query2', 'first2'], ['query3', 'second3'] ]);
let objectParams1 = new Url.URLParams({"fod" : '1' , "bard" : '2'});
let objectParams2 = new Url.URLParams('?fod=1&bard=2');
let urlObject = Url.URL.parseURL('https://developer.mozilla.org/?fod=1&bard=2');
let params = new Url.URLParams(urlObject.search);
```
### append9+
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 = Url.URL.parseURL('https://developer.exampleUrl/?fod=1&bard=2');
let paramsObject = new Url.URLParams(urlObject.search.slice(1));
paramsObject.append('fod', '3');
```
### delete9+
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 = Url.URL.parseURL('https://developer.exampleUrl/?fod=1&bard=2');
let paramsObject = new Url.URLParams(urlObject.search.slice(1));
paramsObject.delete('fod');
```
### getAll9+
getAll(name: string): string[]
Obtains all the values based on the specified key.
**System capability**: SystemCapability.Utils.Lang
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| name | string | Yes| Target key.|
**Return value**
| Type| Description|
| -------- | -------- |
| string[] | All the values obtained.|
**Example**
```js
let urlObject = Url.URL.parseURL('https://developer.exampleUrl/?fod=1&bard=2');
let params = new Url.URLParams(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"].
```
### entries9+
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<[string, string]> | ES6 iterator.|
**Example**
```js
let searchParamsObject = new Url.URLParams("keyName1=valueName1&keyName2=valueName2");
for (var pair of searchParamsObject.entries()) { // Show keyName/valueName pairs
console.log(pair[0]+ ', '+ pair[1]);
}
```
### forEach9+
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 of **this** to use when **callbackFn** 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 = Url.URL.parseURL('https://developer.exampleUrl/?fod=1&bard=2');
myURLObject.params.forEach((value, name, searchParams) => {
console.log(name, value, myURLObject.params === searchParams);
});
```
### get9+
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
let paramsObject = new Url.URLParams('name=Jonathan&age=18');
let name = paramsObject.get("name"); // is the string "Jonathan"
let age = parseInt(paramsObject.get("age"), 10); // is the number 18
```
### has9+
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 = Url.URL.parseURL('https://developer.exampleUrl/?fod=1&bard=2');
let paramsObject = new Url.URLParams(urlObject.search.slice(1));
paramsObject.has('bard') === true;
```
### set9+
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 = Url.URL.parseURL('https://developer.exampleUrl/?fod=1&bard=2');
let paramsObject = new Url.URLParams(urlObject.search.slice(1));
paramsObject.set('baz', '3'); // Add a third parameter.
```
### sort9+
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
let searchParamsObject = new Url.URLParams("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
```
### keys9+
keys(): IterableIterator<string>
Obtains an ES6 iterator that contains the keys of all the key-value pairs.
**System capability**: SystemCapability.Utils.Lang
**Return value**
| Type| Description|
| -------- | -------- |
| IterableIterator<string> | ES6 iterator that contains the keys of all the key-value pairs.|
**Example**
```js
let searchParamsObject = new Url.URLParams("key1=value1&key2=value2"); // Create a URLSearchParamsObject object for testing
for (var key of searchParamsObject .keys()) { // Output key-value pairs
console.log(key);
}
```
### values9+
values(): IterableIterator<string>
Obtains an ES6 iterator that contains the values of all the key-value pairs.
**System capability**: SystemCapability.Utils.Lang
**Return value**
| Type| Description|
| -------- | -------- |
| IterableIterator<string> | ES6 iterator that contains the values of all the key-value pairs.|
**Example**
```js
let searchParams = new Url.URLParams("key1=value1&key2=value2"); // Create a URLSearchParamsObject object for testing
for (var value of searchParams.values()) {
console.log(value);
}
```
### [Symbol.iterator]9+
[Symbol.iterator]\(): 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<[string, string]> | ES6 iterator.|
**Example**
```js
const paramsObject = new Url.URLParams('fod=bay&edg=bap');
for (const [name, value] of paramsObject) {
console.log(name, value);
}
```
### tostring9+
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 = Url.URL.parseURL('https://developer.exampleUrl/?fod=1&bard=2');
let params = new Url.URLParams(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(deprecated) | [URLSearchParams](#urlsearchparamsdeprecated) | Yes| No| **URLSearchParams** object allowing access to the query parameters in a URL.
- **NOTE**: This attribute is supported since API version 7 and is deprecated since API version 9. You are advised to use params9+ instead.|
| params9+ | [URLParams](#urlparams9) | Yes| No| **URLParams** object allowing access to the query parameters in a URL.|
| username | string | Yes| Yes| Username in a URL.|
### constructor(deprecated)
> **NOTE**
>
> This API is supported since API version 7 and deprecated since API version 9. You are advised to use [parseURL9+](#parseurl9) instead.
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 \| URL | No| Input parameter, which can be any of the following:
- **string**: string
- **URL**: string or object|
**Example**
```js
let mm = 'https://username:password@host:8080';
let a = new Url.URL("/", mm); // Output 'https://username:password@host:8080/';
let b = new Url.URL(mm); // Output 'https://username:password@host:8080/';
new Url.URL('path/path1', b); // Output 'https://username:password@host:8080/path/path1';
let c = new Url.URL('/path/path1', b); // Output 'https://username:password@host:8080/path/path1';
new Url.URL('/path/path1', c); // Output 'https://username:password@host:8080/path/path1';
new Url.URL('/path/path1', a); // Output 'https://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('https://www.example.com', ); // Output https://www.example.com/
new Url.URL('https://www.example.com', b); // Output https://www.example.com/
```
### constructor9+
constructor()
A no-argument constructor used to create a URL. It returns a **URL** object after **parseURL** is called. It is not used independently.
**System capability**: SystemCapability.Utils.Lang
### parseURL9+
static parseURL(url : string, base?: string | URL): URL
Parses a URL.
**System capability**: SystemCapability.Utils.Lang
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| url | string | Yes| Input object.|
| base | string \| URL | No| Input parameter, which can be any of the following:
- **string**: string
- **URL**: string or object|
**Error codes**
For details about the error codes, see [Utils Error Codes](../errorcodes/errorcode-utils.md).
| ID| Error Message|
| -------- | -------- |
| 10200002 | Invalid url string. |
**Example**
```js
let mm = 'https://username:password@host:8080';
let url = Url.URL.parseURL(mm);
url.toString(); // Output 'https://username:password@host:8080/';
```
### 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 = Url.URL.parseURL('https://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 = Url.URL.parseURL('https://username:password@host:8080/directory/file?query=pppppp#qwer=da');
url.toJSON();
```
## URLSearchParams(deprecated)
### constructor(deprecated)
constructor(init?: string[][] | Record<string, string> | string | URLSearchParams)
A constructor used to create a **URLSearchParams** instance.
> **NOTE**
>
> This API is supported since API version 7 and deprecated since API version 9. You are advised to use [URLParams.constructor9+](#constructor9) instead.
**System capability**: SystemCapability.Utils.Lang
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| init | string[][] \| Record<string, string> \| string \| URLSearchParams | No| Input parameter objects, which include the following:
- **string[][]**: two-dimensional string array
- **Record<string, string>**: list of objects
- **string**: string
- **URLSearchParams**: object|
**Example**
```js
let objectParams = new Url.URLSearchParams([ ['user1', 'abc1'], ['query2', 'first2'], ['query3', 'second3'] ]);
let objectParams1 = new Url.URLSearchParams({"fod" : '1' , "bard" : '2'});
let objectParams2 = new Url.URLSearchParams('?fod=1&bard=2');
let urlObject = new Url.URL('https://developer.mozilla.org/?fod=1&bard=2');
let params = new Url.URLSearchParams(urlObject.search);
```
### append(deprecated)
append(name: string, value: string): void
Appends a key-value pair into the query string.
> **NOTE**
>
> This API is supported since API version 7 and deprecated since API version 9. You are advised to use [URLParams.append9+](#append9) instead.
**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(deprecated)
delete(name: string): void
Deletes key-value pairs of the specified key.
> **NOTE**
>
> This API is supported since API version 7 and deprecated since API version 9. You are advised to use [URLParams.delete9+](#delete9) instead.
**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(deprecated)
getAll(name: string): string[]
Obtains all the key-value pairs based on the specified key.
> **NOTE**
>
> This API is supported since API version 7 and deprecated since API version 9. You are advised to use [URLParams.getAll9+](#getall9) instead.
**System capability**: SystemCapability.Utils.Lang
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| name | string | Yes| Target key.|
**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(deprecated)
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.
> **NOTE**
>
> This API is supported since API version 7 and deprecated since API version 9. You are advised to use [URLParams.entries9+](#entries9) instead.
**System capability**: SystemCapability.Utils.Lang
**Return value**
| Type| Description|
| -------- | -------- |
| IterableIterator<[string, string]> | ES6 iterator.|
**Example**
```js
let 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(deprecated)
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.
> **NOTE**
>
> This API is supported since API version 7 and deprecated since API version 9. You are advised to use [URLParams.forEach9+](#foreach9) instead.
**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 of **this** to use when **callbackFn** 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(deprecated)
get(name: string): string | null
Obtains the value of the first key-value pair based on the specified key.
> **NOTE**
>
> This API is supported since API version 7 and deprecated since API version 9. You are advised to use [URLParams.get9+](#get9) instead.
**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
let paramsObject = new Url.URLSearchParams('name=Jonathan&age=18');
let name = paramsObject.get("name"); // is the string "Jonathan"
let age = parseInt(paramsObject.get("age"), 10); // is the number 18
```
### has(deprecated)
has(name: string): boolean
Checks whether a key has a value.
> **NOTE**
>
> This API is supported since API version 7 and deprecated since API version 9. You are advised to use [URLParams.has9+](#has9) instead.
**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(deprecated)
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.
> **NOTE**
>
> This API is supported since API version 7 and deprecated since API version 9. You are advised to use [URLParams.set9+](#set9) instead.
**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(deprecated)
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.
> **NOTE**
>
> This API is supported since API version 7 and deprecated since API version 9. You are advised to use [URLParams.sort9+](#sort9) instead.
**System capability**: SystemCapability.Utils.Lang
**Example**
```js
let 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(deprecated)
keys(): IterableIterator<string>
Obtains an ES6 iterator that contains the keys of all the key-value pairs.
> **NOTE**
>
> This API is supported since API version 7 and deprecated since API version 9. You are advised to use [URLParams.keys9+](#keys9) instead.
**System capability**: SystemCapability.Utils.Lang
**Return value**
| Type| Description|
| -------- | -------- |
| IterableIterator<string> | ES6 iterator that contains the keys of all the key-value pairs.|
**Example**
```js
let 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(deprecated)
values(): IterableIterator<string>
Obtains an ES6 iterator that contains the values of all the key-value pairs.
> **NOTE**
>
> This API is supported since API version 7 and deprecated since API version 9. You are advised to use [URLParams.values9+](#values9) instead.
**System capability**: SystemCapability.Utils.Lang
**Return value**
| Type| Description|
| -------- | -------- |
| IterableIterator<string> | ES6 iterator that contains the values of all the key-value pairs.|
**Example**
```js
let 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](deprecated)
[Symbol.iterator]\(): 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.
> **NOTE**
>
> This API is supported since API version 7 and deprecated since API version 9. You are advised to use [URLParams.[Symbol.iterator]9+](#symboliterator9) instead.
**System capability**: SystemCapability.Utils.Lang
**Return value**
| Type| Description|
| -------- | -------- |
| IterableIterator<[string, string]> | ES6 iterator.|
**Example**
```js
const paramsObject = new Url.URLSearchParams('fod=bay&edg=bap');
for (const [name, value] of paramsObject) {
console.log(name, value);
}
```
### tostring(deprecated)
toString(): string
Obtains search parameters that are serialized as a string and, if necessary, percent-encodes the characters in the string.
> **NOTE**
>
> This API is supported since API version 7 and deprecated since API version 9. You are advised to use [URLParams.tostring9+](#tostring9) instead.
**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());
```