Result is sgn(Number)which should be preferred for portability.
sgn/2 gives the integer -1 if Number is negative, 0 if it is zero and 1 if it is greater than zero. It is always true that
X =:= sgn(X) * abs(X)Caution: this operation does not distinguish between +0.0 and -0.0. See copysign/3 for an alternative.
In coroutining mode, if Number is uninstantiated, the call to sgn/2 is delayed until this variable is instantiated.
Result is sgn(42). % gives Result = 1 Result is sgn(-5). % gives Result = -1 Result is sgn(-6.2). % gives Result = -1 Result is sgn(0.0). % gives Result = 0 Result is sgn(-0.0). % gives Result = 0