how to push things in an array in a certain spot in js code example

Example 1: insert into array js

// for me lol... pls don't delete!
// use splice to insert element
// arr.splice(index, numItemsToDelete, item); 
var list = ["hello", "world"]; 
list.splice( 1, 0, "bye"); 
//result
["hello", "bye", "world"]

Example 2: array insertion javascript

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