Exclusive OR

An important Boolean function is the bitwise exclusive or function ⊕ :

a	b	a ⊕ b
0	0	0
0	1	1
1	0	1
1	1	0

Sometimes called a half-adder or XOR, ⊕ is true if a or b is true, but not both. The Java operator for ⊕ is ^.

An important fact is that (a ⊕ b) ⊕ b = a.

Exclusive OR has many important uses:

• Cryptography: text ⊕ code looks like garbage, but another ⊕ code recovers the text.