ErrorCheckingLoops

import javax.swing.JOptionPane;

public class ErrorCheckingLoops {
    public static void main(String[] args) {
        char a;
        do {
            a = JOptionPane.showInputDialog("enter a lower case letter").charAt(0);

        }while((int)a < 97 || (int)a >122);
        System.out.println(a);

        int b;
        do {
            b = Integer.parseInt(JOptionPane.showInputDialog("enter a negative int"));

        }while(b > -1);
        System.out.println(b);

        int c;
        do {
            c = Integer.parseInt(JOptionPane.showInputDialog("enter an even int"));

        }while(c%2 != 0);
        System.out.println(c);
    }
}