How to Parse JSON Data in JavaScript?

How to Parse JSON Data in JavaScript?

Last Updated : 18 Jan, 2025

To parse JSON data in JavaScript, you can use the JSON.parse() method. This method converts a JSON string into a JavaScript object, making it easier to work with the data.

1. Parse Simple JSON Strings

JavaScript

//Driver Code Starts
const jsonS = '{"name": "Rahul", "age": 25, "city": "Mumbai"}';
//Driver Code Ends

const obj = JSON.parse(jsonS);

//Driver Code Starts
console.log(obj.name);
//Driver Code Ends

Output

Rahul

The string is in JSON format.
JSON.parse() converts it into a JavaScript object.
You can access the object properties using dot notation or brackets.

2. Parse JSON Array Strings

JavaScript

//Driver Code Starts
const jsonA = '[{"name": "Anjali"}, {"name": "Vikas"}]';
//Driver Code Ends

const a = JSON.parse(jsonA);
a.forEach(person =>
	console.log(person.name));

Output

Anjali
Vikas

The JSON string represents an array of objects.
After parsing, you can iterate through the array and access each object.

3. Parse Nested JSON

JavaScript

//Driver Code Starts
const nested = '{"person": {"name": "Ravi", "address": {"city": "Delhi", "pin": 110001}}}';
//Driver Code Ends

const obj = JSON.parse(nested);
console.log(obj.person.address.city);

Output

Delhi

JSON.parse() handles nested objects seamlessly.
You can access nested properties using chained dot notation.

4. Parse JSON with Validation

JavaScript

//Driver Code Starts
const jsonS = '{"name": "Pooja", "age": 28}';
//Driver Code Ends

try {
    const obj = JSON.parse(jsonS);
    console.log(obj);
} catch (e) {
    console.error("Invalid JSON:", e.message);
}

Output

{ name: 'Pooja', age: 28 }

Wrapping JSON.parse() in a try...catch block handles invalid JSON inputs.
This is especially useful when dealing with external or unverified data.

5. Parse JSON with a Reviver Function

JavaScript

//Driver Code Starts
const jsonS = '{"name": "Amit", "age": "30"}';
//Driver Code Ends

const obj = JSON.parse(jsonS, (key, value) => {
    if (key === "age") return parseInt(value);
    return value;
});

//Driver Code Starts
console.log(obj.age);
//Driver Code Ends

Output

A reviver function lets you transform values during parsing.
Here, the age is converted from a string to a number.

How to Parse JSON Data in JavaScript?

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