Series: bit “Wise”

Javascript’s bitwise operators are probably the least used and least widely understood part of the language: In the domain of the web, where Javascript enjoys unrivaled supremacy, operating on the bits-and-bytes level is often abstracted away (perhaps thankfully). Despite this, there remain practical uses for the language’s bitwise operators both on the web (for performance reasons) and especially in the burgeoning field of physical computing (Arduino, RaspberryPi, etc.), where Javascript is being embedded in and interacting with things like sensor packages, shift registers and other electronic components that “speak binary”. In this series of Kata, we’ll familiarize ourselves with some of the “basic moves” of the JS bitwise operators.

Exercise 1: XOR-cism

In this Kata, you will be writing a function named "swapper" that should "swap" two integer values (a and b) and return them in an array in "swapped" order. Do your best to complete the kata without declaring any variables or functions and using only bitwise operators in the body of the 'swapper' function. There are some pre-loaded hints you can access if you need help doing it with the bitwise operators. Good luck.

E.G.

var x = swapper(0,1); //returns [1, 0]
Test.expect(x[0] == 1);
Test.expect(x[1] == 0);

x = swapper(1,2);
Test.expect(x[0] == 2);
Test.expect(x[1] == 1);