Java: Interleaving multiple arrays into a single array

Question

I found similar question about interleaving two arraylists into one, but its in PHP. I was asked this question in interview as well but could\'nt solve it, came back to SO t

Answer 1

I believe the mod (%) operations in Matt's answer are incorrect. Under the same assumption (that the arrays are the same length), I'd propose the following solution instead:

static int[] merge(final int[] a, final int[] b)
{
    final int[] result = new int[a.length * 2];

    for (int i=0; i < a.length; i++)
    {
        result[i << 1] = a[i];
        result[(i << 1) + 1] = b[i];
    }

    return result;
}

I tested (very briefly), and it appears to work, but of course makes no attempt to handle error conditions such as null arguments or input arrays mismatched in size.