Signed zero is
zero with an associated
sign. In ordinary arithmetic, the number 0 does not have a sign, so that -0, +0 and 0 are identical. However, in
computing, some number representations allow for the existence of two zeros, often denoted by
-0 (
negative zero) and
+0 (
positive zero), regarded as equal by the numerical comparison operations but with possible different behaviors in particular operations. This occurs in the
sign and magnitude and
ones' complement signed number representations for integers, and in most
floating-point number representations. The number 0 is usually encoded as +0, but can be represented by either +0 or -0.