How to check in node.js if variable is JSON object?

Question

I have variable for example

var x = "this is X value";

How to check in node.js if variable is JSON object ?

If you expect JSON input, you should use JSON.parse. Surround it will try { ... } catch { ... }. If there is an exception, it was not valid JSON input. — Linus Thiel
– Linus Thiel, Commented Sep 4, 2012 at 12:09
This question is similar to: How to check if a string is a valid JSON string?. If you believe it’s different, please edit the question, make it clear how it’s different and/or how the answers on that question are not helpful for your problem. — Nabi K.A.Z.
– Nabi K.A.Z., Commented Sep 30, 2024 at 6:06

Mahn · Accepted Answer · 2012-09-04 18:39:48Z

55

Your question is not clear, but assuming you meant to check if a variable has an unparsed JSON string:

try {
    JSON.parse(x);
} catch (e) {
    console.log("not JSON");
}

answered Sep 4, 2012 at 12:13

Mahn

16.7k17 gold badges66 silver badges82 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

this will not work if the string is a number, like JSON.parse(11) is 11 , no errors