Rand() producing the same results every run

Question

I am entireley new to coding, and am coding a program to simulate catching pokemon. I have a bunch of random numbers being generated during it, but the one that randomizes which pokemon (In int main()) is not randomizing, its only producing "1". Forgive my chaotic coding.

This is the int main

int main(){
srand(time(0));
int Pokemon = rand() % 3 + 1;
if (Pokemon = 1)
{
    Pokemon1();
}
else if (Pokemon = 2)
{
    Pokemon2();
}
else
{
    Pokemon3();
}
return 0;

}

It is calling the other functions. The same thing is happening when randomizing the Pokeball, it allways chooses Ultra Ball

srand(time(NULL));
int BallTypeRand = rand() % 100 + 1;
if (1 < BallTypeRand < 21)
{
    BallType = 1;
    BallName = "Ultra Ball";
    BallCatchRate = 63;
}
else if (21 < BallTypeRand < 51)
{
    BallType = 2;
    BallName = "Great Ball";
    BallCatchRate = 41;
}
else 
{
    BallType = 3;
    BallName = "Poke Ball";
    BallCatchRate = 28;
}

Anyone got any ideas?

Headers are

#include <iostream>
#include <string>
#include <cstdio>
#include <cstdlib>
#include <ctime> 
#include <cmath>
using namespace std;

always turn on all warnings. The compiler will show you the issue in `Pokemon = 1` and `1 < BallTypeRand < 21` immediately — phuclv, Jul 20 '22 at 16:08
For C++ use the mechanisms provided in the `` header, `srand` is a "C" left over. And with the random header you will have better control over your distributions. Doing a rand() + modular operator will not be completely random. See : https://en.cppreference.com/w/cpp/numeric/random — Pepijn Kramer, Jul 20 '22 at 16:12
If you are going to use `rand()` then, in most cases, you should only call `srand()` once to seed the random sequence. Use it once near the beginning of `main()`, not every time you call `rand()`. — Blastfurnace, Jul 20 '22 at 18:50

score 2 · Answer 1 · answered Jul 20 '22 at 16:08

2

= is an assignment operator. Use == operator for checking equality.
Expressions like 1 < BallTypeRand < 21 is interpreted as (1 < BallTypeRand) < 21. The result of 1 < BallTypeRand will be interpreted as 0 or 1, so this expression will always be true. You should use logical AND operator like 1 < BallTypeRand && BallTypeRand < 21.

answered Jul 20 '22 at 16:08

MikeCAT

73,922
11
45
70

Thank you, that fixed the issue with the balls. Do you have any suggestions for the first issue, where the Pokémon is not randomized? – Sylvia Bellefeuille Jul 20 '22 at 16:18
@SylviaBellefeuille I have already posted a suggestion: Use operator `==` instead of `=`. – MikeCAT Jul 20 '22 at 16:19
Ahh, I did not know it was refering to the main issue. That also fixed it, Dankeschön – Sylvia Bellefeuille Jul 20 '22 at 16:22
@SylviaBellefeuille as mentioned earlier, you really, REALLY want to turn on your compiler's warnings. Your compiler wants to point out these typos to you! – Drew Dormann Jul 20 '22 at 16:23
I do not know how, I am still new to it. I am using Embarcadero Dev-C++ – Sylvia Bellefeuille Jul 20 '22 at 16:37

Rand() producing the same results every run

1 Answers1