rand

Go Up to stdlib.h Index

Header File

stdlib.h

Category

Math Routines

Prototype

int rand(void);

Description

Random number generator.

rand uses a multiplicative congruential random number generator with period 2 to the 32nd power to return successive pseudo-random numbers in the range from 0 to RAND_MAX. The symbolic constant RAND_MAX is defined in stdlib.h.

Return Value

rand returns the generated pseudo-random number.

Example

#include <stdlib.h>
#include <stdio.h>
int main(void)
{
    int i;
    randomize();
    printf("Ten random numbers from 0 to 99\n\n");
    for(i=0; i<10; i++)
       printf("%d\n", rand() % 100);
    return 0;
}

Portability

POSIX	Win32	ANSI C	ANSI C++
+	+	+	+