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checking for valid data

Started by Newbie-O-Rama Sep 8, 2000 at 9:23 PM 4 replies 250+ views

Original Post

Sep 8, 2000 at 9:23 PM

OK, here is the newbie question of the night: If I write something like this: void decide(); int choice; cout << "Choose ''1'' or ''2''." << endl; cin >> choice; if (choice==11) { cout << "1"; } if (choice==2) { cout << "2"; } else if (!=2) { void decide(); } } How can I keep it from aborting if someone enters a ''3'' or a ''b'' when the program is run? Thank you.

Newbie-O-Rama

Author

Newbie-O-Rama

Sep 8, 2000 at 9:31 PM

Oops, typo there, I meant:

if (choice==1)

not:

if (choice==11)

dumb fingers......

Quantum

Sep 8, 2000 at 9:40 PM

your code there is a little confusing.. is that supposed to be inside the function?
try this:

        
void decide()
{
     int choice;
     do
     {
          cout << "Choose '1' or '2'." << endl;
          cin >> choice;

          if(choice==1)
               cout << "1";

          else if(choice==2)
               cout << "2";
      } while((choice!=1) && (choice!=2));
}

Edited by - Quantum on September 8, 2000 10:49:56 PM

Newbie-O-Rama

Author

Newbie-O-Rama

Sep 8, 2000 at 9:57 PM

Hey thanks!!!!!!!
It almost worked! It did not abort when I entered a wrong number, but when I tested it by entering a "b", it went into an endless loop (nasty things, really).
Is there another line or two of code to take care of letter input?
thanks again.

Null and Void

163

Null and Void

Sep 8, 2000 at 10:24 PM

Yeah, cin >> ints, will loop up when you input a character.

Try including stdio.h and using scanf instead (scanf(choice,"%i"))

OR

You can change choice to a character (char). Then use ''1'' instead of 1. That will keep it from locking up...

Newbie-O-Rama

Author

Newbie-O-Rama

Sep 8, 2000 at 10:35 PM

THANK YOU!!!!!!!!!!!!
As you can tell, I''m fairly new (very new actually), and I appreciate your responses. I almost did not post because of all the "bad" responses I''ve seen to other newbie questions, but when I can''t find it in my school books, I have to ask someone, and everyone was new once, so it irks me when flames are sent to someone who is trying to learn.
You guys rock.

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