Why Are Two Identical JavaScript Objects Unequal?

The Perplexity of Object Equality

Despite sharing identical characteristics, two seemingly identical objects remain unequal in JavaScript. This phenomenon has perplexed many, given the code snippet below:

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

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

Understanding Equality Operators

The disparity between the results of the regular (==) and strict (===) equality operators lies in type conversion. Regular equality performs implicit type conversion, while strict equality does not. However, in this case, both variables are objects, so type conversion is irrelevant.

Object Identity

Object comparisons evaluate to true only when comparing the same object reference, regardless of the equality operator used. In other words, a == a, a == b (if b is an alias of a), but a != c (if c is a different object).

Implications

This unique behavior has implications for object-oriented programming. Two objects with identical properties but different references are considered unequal, even if they represent the same real-world entity.

For example, in a database, two objects representing the same person with the same name, address, and phone number would not be considered equal, as they have different object references. This can lead to confusing results when performing object comparisons.

Solutions

If comparing the properties of two objects is necessary, consider using a third-party library or implementing a custom comparison function that checks each property individually.

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