In this tutorial, we will show you how to parse a JSON string in TypeScript. There are various ways to do it, but the most common one is using the JSON.parse() method.
Parse a JSON string in TypeScript
Method 1: Using JSON.parse()
All the data that we receive from the web server are strings. And since then, if we try to access it poverty like this:
Example 1:
const jsonString = '{ "name": "LearnShareIt.com", "year": 2022 }';
console.log(jsonString.name);
console.log(jsonString.year);
Output:
undefined
undefined
To deal with that, JavaScript has supported us with the JSON.parse() method to turn strings into objects.
As TypeScript is a superset of JavaScript (the code you write in JavaScript will be basically runnable in TypeScript), we can use the JSON.parse() just the same as we would in JavaScript.
Syntax:
JSON.parse(text, reviver)
Parameters:
- text: the string to parse
- reviver (optional): a function that modifies the result before returning.
Return value: Object, Array, string, number, boolean, or null value based on the given JSON text.
Let’s apply that to fix example 1:
const jsonString = '{ "name": "LearnShareIt.com", "year": 2022 }';
const result = JSON.parse(jsonString);
console.log(result.name);
console.log(result.year);
Output:
LearnShareIt.com
2022
The JSON string is now work as an object, and we can access its properties just like a normal JSON object. Example 2:
type person = {
name: string ;
age: number;
job: string;
phone: string;
address: string;
};
var myString = '{ "name": "Tom", "age": 25, "job": "teacher", "phone": "0123456789", "address": "123xyz" }';
let obj: person = JSON.parse(myString);
console.log(obj);
console.log(obj.name);
console.log(obj.age);
Output:
{
name: 'Tom',
age: 25,
job: 'teacher',
phone: '0123456789',
address: '123xyz'
}
Tom
25
Method 2: With type assertion
In our two examples above, we explicitly type our object so that the object will not get the type any. Besides that, you can also always use a type assertion to set the type of a parsed value.
const obj = JSON.parse(myString) as person;
Completed code for example 2:
type person = {
name: string ;
age: number;
job: string;
phone: string;
address: string;
};
var myString = '{ "name": "Tom", "age": 25, "job": "teacher", "phone": "0123456789", "address": "123xyz" }';
let obj = JSON.parse(myString) as person ;
console.log(obj);
Output:
{
name: 'Tom',
age: 25,
job: 'teacher',
phone: '0123456789',
address: '123xyz'
}
Summary
This tutorial has guided you step by step on how to parse a JSON string in TypeScript. The idea is to use the built-in method JSON.parse() and type our object so that it will not get the type of ‘any’.
Maybe you are interested:
- Import a JavaScript file into a TypeScript file
- How to write to a File using TypeScript
- How to generate a tsconfig.json file
- Capitalize the first letter of a String in TypeScript

Hello. My name is Khanh Hai Ngo. I graduated in Information Technology at VinUni. My advanced programming languages include C, C++, Python, Java, JavaScript, TypeScript, and R, which I would like to share with you. You will benefit from my content.
Name of the university: VinUni
Major: EE
Programming Languages: C, C++, Python, Java, JavaScript, TypeScript, R