How to add an item at the beginning of an array in JavaScript

Say you want to add an item at the beginning of an array.

To perform this operation you will use the splice() method of an array.

splice() takes 3 or more arguments. The first is the start index: the place where we’ll start making the changes. The second is the delete count parameter. We’re adding to the array, so the delete count is 0 in all our examples. After this, you can add one or many items to add to the array.

To add at the first position, use 0 as the first argument:

const colors = ['yellow', 'red']

colors.splice(0, 0, 'blue')

//colors === ['blue', 'yellow', 'red']