Check if a string is a valid JSON string using JavaScript

In order to check the validity of a string whether it is a JSON string or not, We’re using the JSON.parse()method with a few variations. JSON.parse() This method parses a JSON string and constructs the JavaScript value or object specified by the string. A reviver function may be provided to do a change on the resulting object before it’s returned. It can be done using the following methods:

Methods to Check if a String is Valid JSON String:

• Using JSON.parse() method
• Using JSON.stringify() method

Method 1: Using JSON.parse() method

The JSON.parse() method in JavaScript is used to parse a JSON string which is written in a JSON format and returns a JavaScript object. 

Syntax:

JSON.parse( text, function)

Example 1: This example checks the validity of JSON string by JSON.parse() method by creating a function. 

Input string is : { "prop_1": "val_1", "prop_2": "val_2" }
true

Example 2: This example is returning false because the property value val_1 is not a string. 

Input string is : { "prop_1": val_1, "prop_2": "val_2" }
false

Example 3: This example is returning true by using the JSON.parse() method along with typechecking of the text. 

Input string is : { "prop_1": 1, "prop_2": "val_2" }
true

Method 2: Using JSON.stringify() method

The JSON.stringify() method in Javascript is used to create a JSON string out of it.

Syntax:

JSON.stringify(value, replacer, space);

Example: In this example, we will try to convert the given object to a string using JSON.stringify() method