Javascript:Array insert between the array

Here 16 is missing between 9 & 25 that we need to insert at that very place.

let arr = [1, 4, 9, 25, 36];

arr.splice(3, 0, 16);

console.log(arr);

Output:

    [1, 4, 9, 16, 25, 36]

splice(3, 0, 16) means:

3 → index where to insert

0 → don't remove anything if 1 remove one element,if 2 remove 2 element

16 → value to insert 

Here  Original array is mutated.

let arr = [1, 4, 9, 25, 36];

arr.splice(3, 0, 16,17,18);

console.log(arr);

Output:

   [

   1,  4,  9, 16,

  17, 18, 25, 36

]

splice(3, 0, 16) //means:

3 → index where to insert

0 → don't remove anything if 1 remove one element,if 2 remove 2 element

 16,17,18 → value to insert