Thread: Why doesnt this work

Hey, im back again. I got a little time to program and so i decided to write a rock paper scissors program.

I am not sure what is wrong with it but it closes after the user inputs somthing. I think i needs it to return a value

Code:

#include <cstdlib>
#include <iostream>

using namespace std;

int rock();
int paper();
int scissors();

int main()
{
    int select;
    
    cout<< "Welcome to Rock, Paper, Scissiors Version 1.0";
    cout<< "\nInstructions:\n";
    cout<< "\nType ( 1 ) to cast rock\n";
    cout<< "Type ( 2 ) to cast paper\n";
    cout<< "Type ( 3 ) to cast paper\n";
    cout<< "\nYour choice :  ";
    cin>> select;
    switch (select)
    {
          case 1:
               rock();
               break;
          case 2:
               cout<<"asdf";//paper();
               break;
          case 3:
               cout<<"ahrt";//scissors();
               break;
          default:
                  cout<< "\nThat was not a selection!\n";
                  break;
                  }
    cin.get();
  }
  
int rock()
{
      int compchoicerock;
      
      compchoicerock = rand() % 3 + 1;
      
      if ( compchoicerock == 1 ){
           cout<< "\nThe computer also chooses rock.\n";
           cout<< "The round ends in a draw.";
           }
     
      else if( compchoicerock == 2 ){
           cout<< "\nThe computer chooses paper, and paper covers rock so you lose!\n";
           }
     
      else if( compchoicerock == 3 ){
           cout<< "\nThe computer chooses scissors, rock smashes scissors so you win!";
           }

}

Frequently Unread Answers - http://faq.cprogramming.com/cgi-bin/...&id=1043284385

Code:

switch (select)
    {
          case 1:
               rock();
               break;
          case 2:
               cout<<"asdf";//paper();
               break;
          case 3:
               cout<<"ahrt";//scissors();
               break;
          default:
                  cout<< "\nThat was not a selection!\n";
                  break;
                  }
    cin.ignore();
    cin.get();
  }
  
int rock()

You need to insert a cin.ignore(); before your cin.get(); like I have shown. Then when the user inputs their guess, the window stays open.

ok that sloved the problem of the window closing, but now i am having trouble with the rand part

Code:

void rock()
{
      int compchoicerock;
      
      compchoicerock = rand() % 3+1 ;
      
      if ( compchoicerock == 1 ){
           cout<< "\nThe computer also chooses rock.\n";
           cout<< "The round ends in a draw.";
           }
     
      else if( compchoicerock == 2 ){
           cout<< "\nThe computer chooses paper, and paper covers rock so you lose!\n";
           }
     
      else if( compchoicerock == 3 ){
           cout<< "\nThe computer chooses scissors, rock smashes scissors so you win!\a\a\a";
           }

}

if i leave the rand as it is i always win, but if i take away the +1 I always lose.
i havent looked at the FAQ yet, but i read rod's tutorial on rand but i didnt understand it

can someone explain please and thank you

wait explain a little bit more. I changed rand so srand and add #include <ctime> but now it gives me errors and the compiler opens up stdlib.h every time i run the debugger

thank you all very much

Originally Posted by xErath

... bad...
system calls a command line interpreter - big overhead
pause can be a malicious program
tons of better alternatives...

Guidelines for safely using system(). Not super convenient, but it works.