How can I copy elements from one array to another of a different type given a particular index in JavaScript?

Question

I have two arrays:

var arrayA = [ 0, 0, 0 ];
var arrayB = new Uint8Array( 2 );
arrayB[0] = 1;
arrayB[1] = 2;

I would like to copy the values from arrayB to a particular index in arrayA.

For example:

arrayB.copyTo( arrayA, 1 );

arrayA would now become:

[0, 1, 2, 0, 0];

Is there a way of doing this in vanilla javascript without using an iterator?

Answer 1

This is called "splicing". I'm not sure why you're using the Uint8Array constructor, but if you are working with two normal arrays, this is how I would do it:

 var arrayA = [0,0,0]; var arrayB = [1, 2]; var spliceArrays = function(arr1, arr2, index) { var arrPart1 = arr1.slice(0, index); var arrPart2 = arr1.slice(index); return (arrPart1.concat(arr2)).concat(arrPart2); }; var spliced = spliceArrays(arrayA, arrayB, 1); console.log(spliced);