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Problem with while loop!

Feb 20, 2017 at 9:26am
spax1111111 (56)
Why when i enter 'q' or 'Q' the while loop executes?

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char choice_fj();

int main()  
{  
 
 int balls;int guess,guesses=0;
 char choice;choice=choice_fj();
 
 while((choice!='q')||(choice!='Q'))
 {  
   
   srand(static_cast<unsigned int>(time(0)));
   balls=rand()%900+100;
   
   while(guess<balls || guess>balls)
   {  
   cout<<"Guess: ";cin>>guess;
   if(guess<balls)cout<<"Too low"<<endl;
   else if(guess>balls)cout<<"Too high"<<endl;
   }
    
   cout<<"Congrats!!!"<<endl;
  choice=choice_fj();
   
 }
 
  
 

return 0;
}

char choice_fj()
{
	char choice;
  cout<<"Play-(Y/y)"<<endl;
  cout<<"Quit-(Q/q)"<<endl;
  cin>>choice;

  return choice;
  
}
Edit & Run
Last edited on Feb 20, 2017 at 9:31am
Feb 20, 2017 at 9:43am
Chervil (7320)
 
 
while((choice!='q')||(choice!='Q'))

The problem here is that at least one of the two conditions is always true, hence the complete expression is always true.


It could better be written as 
 
 
while(   !(choice=='q' || choice=='Q')   )

or
 
 
while((choice!='q') && (choice!='Q'))

or
 
 
while( std::toupper(choice) !='Q'  )

the last requires #include <cctype>
Feb 20, 2017 at 9:51am
spax1111111 (56)
aaaaaaaaahaaaaa yes i can't believe i did this again thx :D
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