RAND_MAX - cppreference.com (original) (raw)
| | | | | ---------------------------------------------- | | | | #define RAND_MAX /*implementation defined*/ | | |
Expands to an integer constant expression equal to the maximum value returned by the function rand(). This value is implementation dependent. It's guaranteed that this value is at least 32767.
[edit] Example
#include <limits.h> #include <stdio.h> #include <stdlib.h> #include <time.h> int main(void) { srand(time(NULL)); // use current time as seed for random generator printf("RAND_MAX: %i\n", RAND_MAX); printf("INT_MAX: %i\n", INT_MAX); printf("Random value on [0,1]: %f\n", (double)rand() / RAND_MAX); }
Possible output:
RAND_MAX: 2147483647 INT_MAX: 2147483647 Random value on [0,1]: 0.362509
[edit] References
C17 standard (ISO/IEC 9899:2018):
7.22/3 General utilities <stdlib.h> (p: 248)
C11 standard (ISO/IEC 9899:2011):
7.22/3 General utilities <stdlib.h> (p: 340)
C99 standard (ISO/IEC 9899:1999):
7.20/3 General utilities <stdlib.h> (p: 306)
C89/C90 standard (ISO/IEC 9899:1990):
4.10 GENERAL UTILITIES <stdlib.h>