How to check if a value exists in an object using JavaScript

Question

I have an object in JavaScript:

var obj = {
   "a": "test1",
   "b": "test2"
}

How do I check that te

Answer 1

The simple answer to this is given below.

This is working because every JavaScript type has a “constructor” property on it prototype”.

let array = []
array.constructor === Array
// => true


let data = {}
data.constructor === Object
// => true