JSON.parse() with reviver

ES5+

Uses a reviver function to transform values during JSON parsing.

Syntax

JSON.parse(text, reviver)

Parameters

text string

The string to parse as JSON

reviver Function

A function that receives key and value, and returns the transformed value

Return Value

any

The transformed JavaScript value

Examples

JavaScript

const json = '{"created":"2024-01-15","count":"42"}';
const obj = JSON.parse(json, (key, value) => {
  if (key === 'created') return new Date(value);
  if (key === 'count') return parseInt(value, 10);
  return value;
});
console.log(obj.created instanceof Date);
console.log(typeof obj.count);

Output:

// true number

Related Methods

JSON.parse() JSON.stringify()