Re: [Dev-C++] Function Syntax C++

[<jar...@ig...>]

On 26 Nov, Olu...@ao... wrote:
> I  want to write a function that will validate my C++ prgram. I want the 
> function to display a message if wrong value type is entered.  For example -
> 
> int number1; 
> cout <<  " Enter your number. The number must be between 1 and 4: " ;
> cin >> number1;
> 
> if the user enter, a char value instead of a int value, i want the function 
> to display a message of violation of variable type.
> 
> Is it possible to write this type of function and what is the syntax.
> 

You can do the following
  after
  cin >> number1;

  if ( ! cin ) { // something went wrong, for interactive input
                 // most probably a format error
    cin.clear();  // clear the error condition
    cin.ignore(10000,'\n'); // ignore upto the end of line (upto 10000 chars)
    cerr << "invalid input - please try again ";
    cin >> number1;
  }

if writing a loop around this, don't forget to offer another exit to
terminate the program.

-- 
Helmut Jarausch

Lehrstuhl fuer Numerische Mathematik
Aachen University
D 52056 Aachen, Germany