What is the most elegant way to do the next stuff: <pre class="prettyprint"><code>int i = oneOrZero; if (i == 0) { i = 1; } else { i = 0; } </code></pre> You can assume that <code>i</code> can have only 1 or 0 value.

<code>i ^= 1;</code> XOR the value with 1. This gives you both ways (in case you need to flip <code>0 <--> 1</code> either way): <pre class="prettyprint"><code>0 ^ 1 = 1 1 ^ 1 = 0 </code></pre>

Most elegant way to change 0 to 1 and vice versa

What is the most elegant way to do the next stuff:

int i = oneOrZero;  if (i == 0) {    i = 1; } else {    i = 0; }

You can assume that i can have only 1 or 0 value.

Which operator changes the binary digit 0 to 1 and vice versa?

i = ( i + 1 ) % 2 , though I think we all agree the subtraction or xor method is better! (Though it has the added benefit of "flipping the switch" for more than binary.)

i ^= 1;

XOR the value with 1. This gives you both ways (in case you need to flip 0 <--> 1 either way):