EN
JavaScript - insert element to array
10
points
In JavaScript, it is not intuitive to insert an element to an array into some index position. Insert an element into some index position operation can be achieved with Array.prototype.splice
method. This article is focused on how to do it.
1. The Array.prototype.splice
method example
// ONLINE-RUNNER:browser;
// index: 0 1 2 3
var array = ['a', 'b', 'c', 'd'];
// inserting 'new item' element into 1st index position
array.splice(1, 0, 'new_item');
console.log(array);
Output:
[ 'a', 'new_item', 'b', 'c', 'd' ]
Notes about
Array.prototype.splice
method:
- takes as first argument index into 1st index position
- takes as second argument number of removed elements - in this case we do not remove elements
- takes as third argument added element