Add two numbers using bitwise operators https://jsfiddle.net/deadshot/ugycbacd/

sum.js

// Based on the following answer : http://codegolf.stackexchange.com/questions/20996/add-without-addition-or-any-of-the-4-basic-arithmetic-operators/21025#21025
var x = 6;
var y = 6;
var result = function () {
    var sum = 0
    while (y) {
        sum = x^=y,y=(y&x^y)<<1
    }
    return sum
};
alert(result());