How to Copy Array by Value in JavaScript

Topic: JavaScript / jQueryPrev|Next

Answer: Use the slice() Method

You can simply use the slice() method to create a copy of a JavaScript array that behaves independently. This method returns a shallow copy of a portion of an array into a new array.

Let's try out the following example to understand how it basically works:

// Original array
var array1 = ["red", "green", "blue"];

// Making a copy
var array2 = array1.slice();

// Adding a new element to copied array
array2.push("pink");

console.log(array2); // Prints: ['red', 'green', 'blue', 'pink']
console.log(array1); // Prints: ['red', 'green', 'blue']

Alternatively, in ES6 you can easily make an independent copy of an array by using the spread operator (...). Let's take a look at an example to understand how it actually works:

// Original array
var array1 = ["red", "green", "blue"];

// Copying the array
var array2 = [...array1];

// Adding a new element to copied array
array2.push("pink");

console.log(array2); // Prints: ['red', 'green', 'blue', 'pink']
console.log(array1); // Prints: ['red', 'green', 'blue']

Related FAQ

Here are some more FAQ related to this topic:

• How to foreach over an array in JavaScript
• How to insert an item into an array at a specific index in JavaScript
• How to remove duplicate values from a JavaScript array
• How to empty an array in JavaScript