@ohos.util.json (JSON Parsing and Generation)

The JSON module provides a series of APIs for converting JSON text into JSON objects or values and converting objects into JSON strings.

NOTE

The initial APIs of this module are supported since API version 12. Newly added APIs will be marked with a superscript to indicate their earliest API version.

Modules to Import

import { JSON } from '@kit.ArkTS';

Transformer

type Transformer = (this: Object, key: string, value: Object) => Object|undefined|null

Defines the type of the conversion result function.

When used as a parameter of JSON.parse, the function is called by each member of the object, allowing for custom data processing or conversion during parsing.

When used as a parameter of JSON.stringify, the function is used to transfer and handle each property of the object being serialized during serialization.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.Utils.Lang

Parameters

Returns

BigIntMode

Enumerates the modes for processing BigInt.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.Utils.Lang

ParseOptions

Describes the parsing options, which can define the mode for processing BigInt.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.Utils.Lang

JSON.parse

parse(text: string, reviver?: Transformer, options?: ParseOptions): Object|null

Parses a JSON string into an ArkTS object or null.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.Utils.Lang

Parameters

Returns

Error codes

For details about the error codes, see Universal Error Codes.

Example

// /entry/src/main/ets/pages/test.ts
export function reviverFunc(key, value) {
  if (key === "age") {
    return value + 1;
  }
  return value;
}

import { JSON } from '@kit.ArkTS';
import { reviverFunc } from './test';

let jsonText = '{"name": "John", "age": 30, "city": "ChongQing"}';
let obj = JSON.parse(jsonText);
console.info((obj as object)?.["name"]);
// Output: John
const jsonTextStr = '{"name": "John", "age": 30}';
let objRst = JSON.parse(jsonTextStr, reviverFunc);
console.info((objRst as object)?.["age"]);
// Output: 31
let options: JSON.ParseOptions = {
  bigIntMode: JSON.BigIntMode.PARSE_AS_BIGINT,
}
let numberText = '{"largeNumber":112233445566778899}';
let numberObj = JSON.parse(numberText,(key: string, value: Object|undefined|null): Object|undefined|null => {
  if(key === "largeNumber") return value;
  return value;
},options) as Object;

console.info((numberObj as object)?.["largeNumber"]);
// Output: 112233445566778899

JSON.stringify

stringify(value: Object, replacer?: (number|string)[]|null, space?: string|number): string

Converts an ArkTS object or array into a JSON string. In the case of a container, linear containers are supported, but non-linear containers are not.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.Utils.Lang

Parameters

Returns

Error codes

For details about the error codes, see Universal Error Codes.

Example

// /entry/src/main/ets/pages/test.ts
export let exportObj = {1: "John", 2: 30, 3: "New York"};

import { JSON } from '@kit.ArkTS';
import { exportObj } from './test';

let arr = [1, 2];
let rstArrStr = JSON.stringify(exportObj, arr);
console.info(rstArrStr);
// Output: "{"1":"John,""2":30}"
interface Person {
  name: string;
  age: number;
  city: string;
}
let inputObj = {"name": "John", "age": 30, "city": "ChongQing"} as Person;
let rstStr = JSON.stringify(inputObj, ["name"]);
console.info(rstStr);
// Output: "{"name":"John"}"
let rstStrSpace = JSON.stringify(inputObj, ["name"], '  ');
console.info(rstStrSpace);
// Output:
/*
"{
  "name": "John"
}"
*/
let rstStrStar = JSON.stringify(inputObj, ["name"], '&&');
console.info(rstStrStar);
// Output:
/*
"{
&&"name": "John"
}"
*/

JSON.stringify

stringify(value: Object, replacer?: Transformer, space?: string|number): string

Converts an ArkTS object or array into a JSON string. In the case of a container, linear containers are supported, but non-linear containers are not.

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.Utils.Lang

Parameters

Returns

Error codes

For details about the error codes, see Universal Error Codes.

Example

// /entry/src/main/ets/pages/test.ts
export function replacer(key: string, value: Object): Object {
  if (typeof value === "string") {
    return value.toUpperCase();
  }
  return value;
}

import { JSON } from '@kit.ArkTS';
import { replacer } from './test';

interface Person {
  name: string;
  age: number;
  city: string;
}
let inputObj = {"name": "John", "age": 30, "city": "ChongQing"} as Person;
let rstStr= JSON.stringify(inputObj, replacer);
console.info(rstStr);
// Output: "{"name":"JOHN,""age":30,"city":"CHONGQING"}"
let rstStrSpace= JSON.stringify(inputObj, replacer, '  ');
console.info(rstStrSpace);
// Output:
/*
"{
  "name": "JOHN",
  "age": 30,
  "city": "CHONGQING"
}"
*/
let rstStrSymbol= JSON.stringify(inputObj, replacer, '@@@');
console.info(rstStrSymbol);
// Output:
/*
"{
@@@"name": "JOHN",
@@@"age": 30,
@@@"city": "CHONGQING"
}"
*/

JSON.has

has(obj: object, property: string): boolean

Checks whether an ArkTS object contains a key. This API can be used for related operations after JSON.parse is called to parse a JSON string. This API supports only valid JSON strings whose outermost layer is in dictionary format (in braces instead of square brackets).

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.Utils.Lang

Parameters

Returns

Error codes

For details about the error codes, see Universal Error Codes.

Example

import { JSON } from '@kit.ArkTS';

const jsonText = '{"name": "John", "age": 30, "city": "ChongQing"}';
let inputObj = JSON.parse(jsonText);
let result = JSON.has(inputObj, "name");
console.info("result = " + result);
// Output: result = true

JSON.remove

remove(obj: object, property: string): void

Removes a key from an ArkTS object. This API can be used for related operations after JSON.parse is called to parse a JSON string. This API supports only valid JSON strings whose outermost layer is in dictionary format (in braces instead of square brackets).

Atomic service API: This API can be used in atomic services since API version 12.

System capability: SystemCapability.Utils.Lang

Parameters

Error codes

For details about the error codes, see Universal Error Codes.

Example

import { JSON } from '@kit.ArkTS';

const jsonText = '{"name": "John", "age": 30, "city": "ChongQing"}';
let inputObj = JSON.parse(jsonText);
JSON.remove(inputObj, "name");
let result = JSON.has(inputObj, "name");
console.info("result = " + result);
// Output: result = false

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