How to check if a string is a valid JSON string in JavaScript without using Try/Catch

Question

Something like:

var jsonString = \'{ \"Id\": 1, \"Name\": \"Coke\" }\';

//should be true
IsJsonString(jsonString);

//should be false
IsJsonString(\"foo\");         


        

Answer 1

Oh you can definitely use try catch to check whether its or not a valid JSON

Tested on Firfox Quantom 60.0.1

use function inside a function to get the JSON tested and use that output to validate the string. hears an example.

    function myfunction(text){

       //function for validating json string
        function testJSON(text){
            try{
                if (typeof text!=="string"){
                    return false;
                }else{
                    JSON.parse(text);
                    return true;                            
                }
            }
            catch (error){
                return false;
            }
        }

  //content of your real function   
        if(testJSON(text)){
            console.log("json");
        }else{
            console.log("not json");
        }
    }

//use it as a normal function
        myfunction('{"name":"kasun","age":10}')