easy to understand function to delete duplicated elements in an array

deleteDuplicates.js

function deleteDuplicates(arr) {
    arr.sort();
    var lastElement = '';
    var arrDuplicate = arr;
    for (var i = arrDuplicate.length; i >= 0; i--) {
        if (arrDuplicate[i] == lastElement) {
            arr.splice(i, 1);
        }
        lastElement = arrDuplicate[i];
    }
    return arr;
}