Generates a pseudorandom number.
int rand( void );
| Routine | Required Header | Compatibility |
| rand | <stdlib.h> | ANSI, Win 95, Win NT |
For additional compatibility information, see Compatibility in the Introduction.
Libraries
| LIBC.LIB | Single thread static library, retail version |
| LIBCMT.LIB | Multithread static library, retail version |
| MSVCRT.LIB | Import library for MSVCRT.DLL, retail version |
Return Value
rand returns a pseudorandom number, as described above. There is no error return.
Remarks
The rand function returns a pseudorandom integer in the range 0 to RAND_MAX. Use the srand function to seed the pseudorandom-number generator before calling rand.
Example
/* RAND.C: This program seeds the random-number generator
* with the time, then displays 10 random integers.
*/
#include <stdlib.h>
#include <stdio.h>
#include <time.h>
void main( void )
{
int i;
/* Seed the random-number generator with current time so that
* the numbers will be different every time we run.
*/
srand( (unsigned)time( NULL ) );
/* Display 10 numbers. */
for( i = 0; i < 10;i++ )
printf( " %6d\n", rand() );
}
Output
6929
8026
21987
30734
20587
6699
22034
25051
7988
10104
Floating-Point Support Routines
See Also srand