Preventing program from crashing when user enters a char instead of a numerical input

[Jay Dobrzyn]

Hi!
Am very new at java (only been doing if, while and so on. No idea of arrays, bufferstrings etc! Presently using consolewindow for input) and my problem is this:
Basically, when I ask the user for a int or a double input and he/she enters a char, then the whole thing hangs; ideally, if the user does that, I'd like the question to be repeated.
eg: c.out.println("Please enter number needed") ;
num = c.input.readInt () ;
I've been able to block sort the other way round, in that the program will loop back to the question should the user enter an int instead of a char by:
if (!(word == 'h') || word == 'r')
and then putting another c.out.println and readString etc underneath.
For my problem I've tried doing whiles and ifs based on (!(num >= 0) %% num <= 0) but within a while statement, all I get is a just a mess!
Is there a simple way to solve this using whiles and ifs?
Thanks!
Robin
[ March 19, 2004: Message edited by: Jay Dobrzyn ]

[Stan James]

Look into try & catch with something like:

boolean done = false
int number = 0;
while(!done)
{
   print "enter a number"
   read a string
   try
   {
      number = Integer.parseInt(string)
      done = true
   }
   catch( Exception e )
   {
      print "That wasn't a number!"
   }
}

If try/catch is new to you, look up exceptions in a good book. Bruce Eckell's Thinking In Java is free online: http://64.78.49.204/