c - Why am I getting "void value not ignored as it ought to be"?

Question

I have the following function :

void getdata(int arr[], int n)
{

    for (int i = 0; i < n; i++) 
    {
        int a = srand(time(NULL));
        arr[i] = a;
    }
}

And I call it in main:

getdata(arr, 1024);

I get "void value not ignored as it ought to be" but I don't understand what is wrong.Why do I get this error?

Answer 1

  int a = srand(time(NULL));

The prototype for srand is void srand(unsigned int) (provided you included <stdlib.h>).
This means it returns nothing ... but you're using the value it returns (???) to assign, by initialization, to a.

---

Edit: this is what you need to do:

#include <stdlib.h> /* srand(), rand() */
#include <time.h>   /* time() */

#define ARRAY_SIZE 1024

void getdata(int arr[], int n)
{
    for (int i = 0; i < n; i++)
    {
        arr[i] = rand();
    }
}

int main(void)
{
    int arr[ARRAY_SIZE];
    srand(time(0));
    getdata(arr, ARRAY_SIZE);
    /* ... */
}