infinite stupidity

**MarlonDean** · 05-20-2008

Code:

using namespace std;
int inputAndValidate(char position,int points)
{
   do{
    cout<<"Please enter the posistion (F or B)"<<endl;
    cin>>position;
    cout<<position<<endl;
   } while(position!='F' || position!='B');
return 0;
}

why does this loop? no matter what input it just loops, please assist the village idiot...

**anon** · 05-20-2008

One of those conditions is always going to be true. A character can't equal 'F' and 'B' at the same time...

**MarlonDean** · 05-20-2008

Ok i understand it like this

do the loop while position does not equal f or equal b...

has my logic gone astray?

**MarlonDean** · 05-20-2008

!= does mean "does not equal", doesn't it?

**anon** · 05-20-2008

The condition that you are looking for:

Code:

while (!(position == 'B' || position == 'F'));

Which is the same as:

Code:

while (position != 'B' && position != 'F');

**MarlonDean** · 05-20-2008

Ok ok i got it, I must use && instead of || because no matter what using the || will always result in the condition being true... thanks anon!

**Elysia** · 05-20-2008

Read the logic out loud:
Loop while position is not equal to 'B' OR position is not equal to 'F'.

Or the other one:
Loop while position is not equal to 'B' AND position is not equal to 'F'.

Tell me which one sounds most reasonable?
It's no different than communicating with a friend, for example, on what he or she should do. It's not programming - it's logic!