signbit(x)
bool signbit (float x); bool signbit (double x); bool signbit (long double x);
int
float
double
long double
bool
true
false
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/* signbit example */ #include <stdio.h> /* printf */ #include <math.h> /* signbit, sqrt */ int main() { printf ("signbit(0.0) : %d\n",signbit(0.0)); printf ("signbit(1.0/0.0) : %d\n",signbit(1.0/0.0)); printf ("signbit(-1.0/0.0) : %d\n",signbit(-1.0/0.0)); printf ("signbit(sqrt(-1.0)): %d\n",signbit(sqrt(-1.0))); return 0; }
signbit(0.0) : 0 signbit(1.0/0.0) : 0 signbit(-1.0/0.0) : 1 signbit(sqrt(-1.0): 1