Swap = function (array, item1, item2)
{
    if (item1 === item2)
    {
        return array;
    }

    var index1 = array.indexOf(item1);
    var index2 = array.indexOf(item2);

    if (index1 < 0 || index2 < 0)
    {
        throw new Error('Supplied items must be elements of the same array');
    }

    array[index1] = item2;
    array[index2] = item1;

    return array;
}
Swaps the position of two elements in the given array.
The elements must exist in the same array.
The array is modified in-place.

@function Phaser.Utils.Array.Swap
@since 3.4.0

@param {array} array - The input array.
@param {*} item1 - The first element to swap.
@param {*} item2 - The second element to swap.

@return {array} The input array.