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']