Have tried :

function isJSON(str) {
    try {
        JSON.parse(str);
    } catch (e) {
        return false;
    }
    return true;
}

To check weather a string is json or not. It returns true for boolean type formats.

Is there any possible way to identify a valid json string in Java Script or in JQuery?

Have tried :

function isJSON(str) {
    try {
        JSON.parse(str);
    } catch (e) {
        return false;
    }
    return true;
}

To check weather a string is json or not. It returns true for boolean type formats.

Is there any possible way to identify a valid json string in Java Script or in JQuery?

• javascript
• jquery

• what do you mean by boolean type formats? – Daniel A. White Commented Aug 16, 2016 at 10:16
• He means isJSON(false) returns true. – Jeremy Thille Commented Aug 16, 2016 at 10:17
• Yeah you were right Jeremy Thille – Tom Taylor Commented Aug 16, 2016 at 11:03

2 Answers 2

To assure you have a valid json you must have a string first

function isJSON(str) {

    if( typeof( str ) !== 'string' ) { 
        return false;
    }
    try {
        JSON.parse(str);
        return true;
    } catch (e) {
        return false;
    }
}

Your function works, just add a boolean check :

function isJSON(str) {

    if(typeof(str) === "boolean"){ return false; } // or if(typeof(str) !== "string")

    try {
        JSON.parse(str);
    } catch (e) {
        return false;
    }
    return true;
}