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

Very Simple one-liner code ( But Hacky approach )

if (expected_json.id === undefined){
   // not a json
}
else{
   // json
}

NOTE: This only works if you are expecting something is JSON string like id. I am using it for an API and expecting the result either in JSON or some error string.