Using Spread Operators for Arrays and Objects In JavaScript

In JavaScript, the spread operator (...) is like a little magic trick you can use to expand elements of an array or properties of an object into somewhere else. It’s like taking a deck of cards and spreading them out on the table. This operator can make working with arrays and objects a lot easier and more fun.

For Arrays

Imagine you have a bunch of fruits in a basket, and you want to add them into a blender to make a smoothie. The spread operator lets you take all those fruits out of the basket and put them into the blender.

I. Combining Arrays

let fruits = ["apple", "banana"];
let moreFruits = ["orange", "pear"];

let allFruits = [...fruits, ...moreFruits];
console.log(allFruits); // ["apple", "banana", "orange", "pear"]

II. Adding Items

You can also add new items into an array without losing the old ones.

let initialFruits = ["apple", "banana"];
let allFruits = [...initialFruits, "kiwi", "melon"];
console.log(allFruits); // ["apple", "banana", "kiwi", "melon"]

III. Copying an Array

And if you want to make a copy of your fruit basket so your friend can have one too, you can do that easily.

let myFruits = ["apple", "banana"];
let friendFruits = [...myFruits];
console.log(friendFruits); // ["apple", "banana"]

For Objects

Now, imagine you have a box of toys, and you want to combine it with your friend’s box of toys. The spread operator lets you do just that, combining all the toys into one big box.

I. Combining Objects

let myToys = { car: "red", ball: "blue" };
let friendToys = { doll: "green", teddy: "brown" };

let allToys = { ...myToys, ...friendToys };
console.log(allToys); // { car: "red", ball: "blue", doll: "green", teddy: "brown" }

II. Adding or Updating Properties

If you get a new toy or want to repaint your car toy, you can also do that.

let myToys = { car: "red", ball: "blue" };
let updatedToys = { ...myToys, car: "green", yoyo: "yellow" };
console.log(updatedToys); // { car: "green", ball: "blue", yoyo: "yellow" }

III. Copying an Object

And just like with the fruits, if you want to make a copy of your toy box to keep one at grandma’s house, it’s super simple.

let myToys = { car: "red", ball: "blue" };
let grandmaToys = { ...myToys };
console.log(grandmaToys); // { car: "red", ball: "blue" }


The spread operator is super handy for working with arrays and objects in JavaScript. Whether you’re combining, adding, or copying, it helps you do it in a clean and understandable way. It’s like having a magic wand to spread things out exactly where you need them.