JSON.parse()
Parses a JSON string and returns the corresponding JavaScript value.
Syntax
JSON.parse(text, reviver)Parameters
| Name | Type | Required | Description |
|---|---|---|---|
text | string | Yes | The JSON string to parse. Must be valid JSON. |
reviver | Function | No | Function (key, value) called for each pair to transform the parsed result. Return undefined to delete a property. |
Returns
any — The JavaScript value (object, array, string, number, boolean, or null).
Throws
SyntaxError— the string is not valid JSON.
Examples
const obj = JSON.parse('{"a":1,"b":[2,3]}');
console.log(obj.a, obj.b);
Output
1 [ 2, 3 ]
const o = JSON.parse('{"n":"5"}', (k, v) => k === 'n' ? Number(v) : v);
console.log(o.n);
Output
5
Notes
Throws a SyntaxError on invalid JSON - wrap in try/catch for untrusted input.
JSON requires double-quoted keys and strings; trailing commas and comments are
not allowed. Dates parse as strings, not Date objects.
Browser & runtime support
| Environment | Since version |
|---|---|
| chrome | 4 |
| firefox | 3.5 |
| safari | 4 |
| edge | 12 |
| node | 0.10 |