Mastering Reference Variables in JavaScript: A Comprehensive Guide

Dive into the world of reference variables in JavaScript with these practical examples

Photo by Florian van Duyn on Unsplash

In JavaScript, understanding how reference variables work is crucial for writing efficient and error-free code. However, many developers find this concept confusing and intimidating. This guide aims to simplify the topic and help you master reference variables in JavaScript. Let’s get started!

What are Reference Variables?

Reference variables store the memory location of an object or array instead of its value. When we assign one variable to another, both variables point to the same memory location, not separate copies. Any changes made to the original object will be reflected in all other references pointing to it.

Example:

let obj = {name: 'John', age: 30};
let refObj = obj;
refObj.age = 35; // Changes to refObj also affect obj
console.log(obj); // Output: { name: 'John', age: 35 }

Pass by Value vs Pass by Reference

JavaScript uses pass by value for primitive types like numbers, strings, booleans, etc., while using pass by reference for objects and arrays.