Why are two identical objects not equal to each other?

Question

Seems like the following code should return a true, but it returns false.

var a = {};
var b = {};

console.log(a==b); //returns false
console.log(a===b); //         


        

Answer 1

Here is a quick explanation of why {} === {} returns false in JavaScript:

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From MDN Web Docs - Working with objects: Comparing objects.

In JavaScript, objects are a reference type. Two distinct objects are never equal, even if they have the same properties. Only comparing the same object reference with itself yields true.

// Two variables, two distinct objects with the same properties
var fruit = {name: 'apple'};
var fruitbear = {name: 'apple'};

fruit == fruitbear; // return false
fruit === fruitbear; // return false

// Two variables, a single object
var fruit = {name: 'apple'};
var fruitbear = fruit;  // Assign fruit object reference to fruitbear

// Here fruit and fruitbear are pointing to same object
fruit == fruitbear; // return true
fruit === fruitbear; // return true

fruit.name = 'grape';
console.log(fruitbear); // output: { name: "grape" }, instead of { name: "apple" }

For more information about comparison operators, see Comparison operators.