rand() only sets variable to 0

Question

I am working on a rock, paper, scissors game and one of the ways I am setting the computer's choice is through rand(). I #include <ctime>, seed rand at the start of main with srand(time(0)); and I call it in a function definition with computerWeaponChoiceV = (rand() % 3) + 1;. However, when I test my program it always prints computerWeaponChoiceV to be 0.

Am I doing something wrong with rand()? If you need more of my code please let me know.

Maybe related: http://stackoverflow.com/questions/2129705/why-is-rand-anything-always-0-in-c?rq=1 — HolyBlackCat, Sep 25 '16 at 21:10
The code you've shown is correct. The problem must be in the code you didn't show. — Pete Becker, Sep 25 '16 at 21:11
`rand()` is never negative, and the modulus will not change this. How can the value then be zero after adding `1`? Have you really run the code snippets you show? — Thomas B Preusser, Sep 25 '16 at 21:13

score -4 · Answer 1 · answered Sep 25 '16 at 21:00

i'm not used with c++ (only programmed with c++ a pair of times) but I think the issue is on rand declaration.

Try using rand() % 3 + 1;

If this don't work regard to time(0), it may take a "NOW" value to properly randomize (usually programming languages take miliseconds to randomize). PD: I may be wrong on what i said of time, comment on there if those two solutions doens't serve you.

There is an example of rand from 1 to 10 working:

/* rand example: guess the number */
#include <stdio.h>      /* printf, scanf, puts, NULL */
#include <stdlib.h>     /* srand, rand */
#include <time.h>       /* time */

int main ()
{
  int iSecret, iGuess;

  /* initialize random seed: */
  srand (time(NULL));

  /* generate secret number between 1 and 10: */
  iSecret = rand() % 10 + 1;

  do {
    printf ("Guess the number (1 to 10): ");
    scanf ("%d",&iGuess);
    if (iSecret<iGuess) puts ("The secret number is lower");
    else if (iSecret>iGuess) puts ("The secret number is higher");
  } while (iSecret!=iGuess);

  puts ("Congratulations!");
  return 0;
}

Cheers!

Changing rand to how you suggested still does nothing, it only prints a 0 — njwoodard, Sep 25 '16 at 21:11
srand (time(NULL)); and computerWeaponChoiceV = rand() % 3 + 1; and, oviously check that you've the proper libraries charged (as i put on the example) — JoelBonetR, Sep 25 '16 at 21:19

rand() only sets variable to 0

1 Answers1