Try and Catch Q2!

[Sam Bluesman]

I now have this code and for some reason it does not do what I want it to do:

while(NOC == 0){

   try{
 
      do{
         System.out.print(" Enter 1 or enter 2 : ");
 NOC = new Integer(keyboardInput.readLine()).intValue();
      }while(NOC!=1 || NOC !=2);
 
   }

   catch (NumberFormatException e2) { 
      System.out.println(" Please enter 1 or 2"); 
   }
    
}
 
while(NOM == 0){
    
   try{
      System.out.print(" Enter Number of operations: ");
      NOM = new Integer(keyboardInput.readLine()).intValue();
   }
    
   catch (NumberFormatException e3) { 
      System.out.println(" Please enter an integer"); 
   }
    
}

It works fine if I press a letter key on the keyboard and the exception if thrown and the request to enter either 1 or 2 is repeated.

However, If i then press, say, 3 i am promted again, but if i then press a letter on the keyboard and press enter, then the user is promted "Please enter an integer", i.e. the next exception (e3) is thrown, rather than the current exception (e2), "Please enter 1 or 2".

What is going on here?

Cheers
[ March 26, 2006: Message edited by: Sam Bluesman ]

[Ernest Friedman-Hill]

When you press 3 NOM is set to 3. It's not zero, so the loop terminates.

The catch block could set NOM back to 0, or the while could say "while (NOM != 1 && NOM != 2)".