Using an array literal is the easiest way to create a JavaScript Array. Syntax: const array_name = [item1, item2, ...]; It is a common practice to declare arrays with the const keyword. Learn more about const with arrays in the chapter: JS Array Const. Spaces and line breaks are not important. A declaration can span multiple lines:

Destructuring assignment makes it possible to extract data from arrays or objects using a syntax that mirrors the construction of array and object literals. The object and array literal expressions provide an easy way to create ad-hoc packages of data.

Feb 20, 2018 · reverseArray(): returns a new array which is the reverse of the argument array. reverseArrayInPlace(): just reverses the argument array itself. Inside reverseArrayInPlace(), I just called reverseArray() to create a new array and reassign to the argument of reverserArrayInPlace().

May 16, 2022 · In this article I showed you three ways to create an array using the assignment operator, Array constructor, and Array.of() method. The most common way to create an array in JavaScript would be to assign that array to a variable like this:

Oct 22, 2024 · Initializing an array in JavaScript involves creating a variable and assigning it an array literal. The array items are enclosed in square bracket with comma-separated elements. These elements can be of any data type and can be omitted for an empty array.

Apr 3, 2025 · Several of the built-in array methods (e.g., join(), slice(), indexOf(), etc.) take into account the value of an array's length property when they're called. Other methods (e.g., push(), splice(), etc.) also result in updates to an array's length property.

JavaScript array is a special type of variable, which can store multiple values using a special syntax. Learn what is an array and how to create, add, remove elements from an array in JavaScript.

How to merge two arrays in JavaScript and de-duplicate items. Use the concat function, like so: The value of newArray will be [1, 2, 3, 4] (arrayA and arrayB remain unchanged; concat creates and returns a new array for the result). I agree that performant execution is very nice. BUT isn't concat exactly for that purpose to concat to arrays?

JavaScript provides you with two ways to create an array. The first one is to use the Array constructor as follows: The scores array is empty, which does hold any elements. If you know the number of elements that the array will hold, you can create an array with an initial size as shown in the following example:

Nov 14, 2022 · There are two standard ways to declare an array in JavaScript. These are either via the array constructor or the literal notation. In case you are in a rush, here is what an array looks like declared both ways: You can continue reading this article to properly understand these methods alongside some other interesting options they possess.