Javascripts methods in arrays

That method is only on code.org https://docs.code.org/applab/insertItem/

But JS has a similar method you can use: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/splice

insertItem() is purely code.org

https://docs.code.org/applab/insertItem/

To do this in regular javascript, you would:

1. If you wanted to insert the item into the end of the array, you would use .push()

var array = [0, 1, 2];

console.log(array);
array.push("item");
console.log(array);

2. If you wanted to replace an item in the array (in which you know the index), you would use array[index] = item;

var array = [0, 1, 2];

console.log(array);
array[1] = "item";
console.log(array);

3. If you wanted to replace an item in an array by knowing the value, but not the index, you would use array[array.indexOf(value)] = item;

var array = [0, 1, 2];

console.log(array);
array[array.indexOf(1)] = "item";
console.log(array);

4. Finally, if you wanted to insert an item into the array, you would use .splice(). To insert an item after index 2, you would use array.splice(2, 0, item).

var array = [0, 1, 2];

console.log(array);
array.splice(1, 0, "item");
console.log(array);

Code.org probably uses the following function to make life easier for you:

var array = [0, 1, 2];

function insertItem(list, index, item) {
  list.splice(index, 0, item);
  return list;
}

console.log(array);
array = insertItem(array, 1, "item");
console.log(array);

There is no method by name insertItem for Array in javascript. Also it seems insertItem(list, index, item) is a function and it accepts three arguments.

You can get list of javascript array methods in this link

There's no JavaScript function named insertItem - however, there's an almost identical method named splice - syntax like list.splice(index, 0, item):

var list = [1, 2, 4];
var item = 3;
var index = 2;
list.splice(index, 0, item);
console.log(list);