1. What is the purpose of while (!validBet) in this code?

[dannyboi]

import javax.swing.JOptionPane;

public class BettingQuestion {

public static void main (String [] args) {

int bank = 1000;
int bet;
boolean validBet;

JOptionPane.showMessageDialog(null, "You can bet between 1 and " + bank);	
do {
bet = Integer.parseInt(
JOptionPane.showInputDialog(null, "Enter your bet:"));
validBet = true;
if (bet <= 0 || bet >1000) {
validBet = false;
JOptionPane.showMessageDialog(null, "What, are you crazy?");
}
} while (!validBet);	

JOptionPane.showMessageDialog(null, "Your money's good here.");
}
}

[Fou-Lu]

! evaluates to NOT. So in this example, do/while validBet is false.