Question

Ok. So I am a total beginner at Java. But why does this loop never end, even if i type in 0 or 1.

do {
   //Ask user to enter 1 or 0           
   System.out.print("Enter 1 or 0: ");
   upOrDown = keyboard.nextInt();

} while(upOrDown != 0 || upOrDown != 1); 
//Here the loop should exit if user entered 1 or 0, but it does not.

So, what am I missing here, probably very obvious and I am sorry 🙁

Answer 1

You need to do an &&.

You’re saying “If the number either isn’t 0 or isn’t 1, then retry.” This’ll always be true, however, as it cannot be both 0 and 1 at the same time.

So, this is what you want:

do {
   //Ask user to enter 1 or 0           
   System.out.print("Enter 1 or 0: ");
   upOrDown = keyboard.nextInt();
} while(upOrDown != 0 && upOrDown != 1);