need help dont understand

Code:

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

int randrange(int low, int high){
return rand()%(high-low+1)+low;
}
int main(){
int a;
srand(time(NULL));
a = randrange(1,2);
for ( int i=0;i<10; ++i)
    {
  cout<<randrange(1,2)<<'\n';
  switch (a){
  case 1:
      cout<<"heads\n";
      break;

  case 2:
    cout<<"tails\n";
    break;
  }

    }
}

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i dont understand why it keep printing heads but not tails even when the random number is 2?

Notice that you do not assign to a within the loop.

Thanks but after i moved it. The heads/ tails is random as well it dont follow 1= head 2=tails. Can ya tell me why is that ? I want to clearly understand this rand() before moving on .. Sorry i just start learning program like a week ago

you should cout the value of a, not the random generated number not related to current value of a

You declared a = randrange(1,2) outside the loop, so it's different with the value of cout<<randrange(1,2) which is changing overtime within the loop, while a will always be the same value. That's why the result is either just heads or tails because the switch referred to the a value which was declared first. I've tried to solve it and it works fine.

CMIIW because I'm also just start learning C++, so I want to ask if there's a specific reason of rand()%(high-low+1)+low ?
Thanks.

Quote:

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Originally Posted by ch1215

CMIIW because I'm also just start learning C++, so I want to ask if there's a specific reason of rand()%(high-low+1)+low ?
Thanks.

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You can try to read this article Generating Random Numbers in C and C++ - Cprogramming.com

Thanks i understand now great help guys