srand() — Set Seed for rand() Function
Format
#include <stdlib.h>
void srand(unsigned int seed);
Language Level
ANSI
Threadsafe
No
Description
The srand()
function
sets the starting point for producing a series of pseudo-random integers.
If srand()
is
not called, the rand()
seed
is set as if srand(1) were called at program start. Any
other value for seed sets the generator
to a different starting point.
The rand()
function
generates the pseudo-random numbers.
Return Value
There is no return value.
Example
This example first calls
srand()
with
a value other than 1 to initiate the random value sequence. Then
the program computes five random values for the array of integers
that are called ranvals. #include <stdlib.h>
#include <stdio.h>
int main(void)
{
int i, ranvals[5];
srand(17);
for (i = 0; i < 5; i++)
{
ranvals[i] = rand();
printf("Iteration %d ranvals [%d] = %d\n", i+1, i, ranvals[i]);
}
}
/****************** Output should be similar to: ****************
Iteration 1 ranvals [0] = 24107
Iteration 2 ranvals [1] = 16552
Iteration 3 ranvals [2] = 12125
Iteration 4 ranvals [3] = 9427
Iteration 5 ranvals [4] = 13152
*/