How to check if a string is a valid json string in javascript?

Hi Friends 👋,

Welcome To Infinitbility! ❤️

Today, I’m going to show you how do I check if a string is a valid JSON string in javascript, here we will use the JSON.parse() method to validate string is a JSON string or not.

The JSON.parse() method parses a JSON string, constructing the JavaScript value or object described by the string. An optional reviver function can be provided to perform a transformation on the resulting object before it is returned.

Let’s start today’s tutorial How to check if a string is a valid JSON string in javascript?

Before going to code, let’s understand what we are going to do?

1. Create a function that validates JSON string
2. Use Date.parse() on in created function with try/catch ( without try/catch hard handle errors show every time when we validate JSON string we should use try/catch block )
3. Create two JSON string variables one is a valid JSON string and the second is an invalid string
4. Use created a function to validate
5. Console which string is a valid

Copy 
1// Create a function which validate json string
2function IsJsonString(str) {
3    // Use `Date.parse()` on in created function with try/catch
4    try {
5        JSON.parse(str);
6    } catch (e) {
7        return false;
8    }
9    return true;
10}
11
12// Create two json string variables one is a valid json string and the second is a invalid string
13let firstJsonStr = '{"name":"infinitbility","domain":"infinitbility.com","age":2}';
14let secondJsonStr = '{nam:infinitbilit,domain:infinitbility.com,age:2}';
15
16// Use created function to validate
17// Console which string is a valid
18if(IsJsonString(firstJsonStr)){
19 console.log("firstJsonStr is a valid") 
20}
21
22if(IsJsonString(secondJsonStr)){
23 console.log("secondJsonStr is a valid") 
24}

When running the above program it should console 'firstJsonStr is a valid' in the log. let’s check the output.

I hope it’s help you, All the best 👍.