C语言库float.h

// -----------------------
#include <stdio.h>
#include <float.h>

int main () {
   printf("The maximum value of float = %.10e\n", FLT_MAX);
   printf("The minimum value of float = %.10e\n", FLT_MIN);
   printf("The number of digits in the number = %.10e\n", FLT_MANT_DIG);
}