add value on 0 index javascript code example

Example 1: javascript push in specific index

arr.splice(index, 0, item);
//explanation:
inserts "item" at the specified "index",
deleting 0 other items before it

Example 2: insert item into array specific index javascript

myArray.splice(index, 0, item);

Example 3: array insertion javascript

Array.prototype.insert = function ( index, item ) {
    this.splice( index, 0, item );
};