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Thread: while instead of if-else

  1. #1
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    Default while instead of if-else

    Hi, I'm taking JAVA JDK2 course in college and I need some help please.

    I need to know how to use (while) statement instead of (if-else) to execute the program again in case if the input is not correct.

    --------------------------------------------------------------------------------------------------------------------------------
    import java.util.Scanner;
    import javax.swing.*;
     
    public class Main {
     
     
        public static void main(String[] args) {
     
            String name;
            String passw;     
     
     
     
     
            name= JOptionPane.showInputDialog("Enter Your Name Please: ");
            if (name.equals("fahad"))
            {
     
    passw=  JOptionPane.showInputDialog("Your Password: ");
     
             if (passw.equals("123"))
             {
                      JOptionPane.showMessageDialog(null, "Welcome " + name + " Successful Login");
             }
     
                else
                {
                 JOptionPane.showMessageDialog(null,"Incorrect input, please exit the program!! ");
                }
     
     
     
            }
             else
            {
               JOptionPane.showMessageDialog(null,"Incorrect input, please exit the program!! ");
            }
     
     
     
     
     
        }
    }
    --------------------------------------------------------------------------------------------------------------------------------

  2. #2
    mmm.. coffee JavaPF's Avatar
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    Default Re: while instead of if-else

    Hello Fahad,

    Welcome to the Java Programming Forums

    How about this?

    import javax.swing.*;
     
    public class Main {
     
    	public static void main(String[] args) {
     
    		[B]boolean locked = true;[/B]
    		String name;
    		String passw;
     
    		name = JOptionPane.showInputDialog("Enter Your Name Please: ");
     
    		[B]while (locked) {[/B]
    			if (name.equals("fahad")) {
     
    				passw = JOptionPane.showInputDialog("Your Password: ");
     
    				if (passw.equals("123")) {
    					JOptionPane.showMessageDialog(null, "Welcome " + name
    							+ " Successful Login");
    					[B]locked = false;[/B]
    				}
     
    				else {
    					JOptionPane.showMessageDialog(null,
    							"Incorrect input, please exit the program!! ");
    				}
     
    			} else {
    				JOptionPane.showMessageDialog(null,
    						"Incorrect input, please exit the program!! ");
    			}
    		[B]}[/B]
    	}
    }
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  3. #3
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    Default Re: while instead of if-else

    thaanks a lot , it worked for the password but it doesn’t worked for the name what should I do?

  4. #4
    mmm.. coffee JavaPF's Avatar
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    Default Re: while instead of if-else

    You could do something like this:

    import javax.swing.*;
     
    public class Main {
     
    	public static void main(String[] args) {
     
    		boolean nameLocked = true;
    		String name;
     
    		name = JOptionPane.showInputDialog("Enter Your Name Please: ");
     
    		while (nameLocked) {
     
    			if (name.equals("fahad")) {
     
    				nameLocked = false;
    				passBox();
     
    			} else {
     
    				name = JOptionPane
    						.showInputDialog("Incorrect Username! Enter Your Name Please: ");
    			}
     
    		}
     
    	}
     
    	public static void passBox() {
     
    		boolean passLocked = true;
    		String passw;
     
    		while (passLocked) {
    			passw = JOptionPane.showInputDialog("Your Password: ");
     
    			if (passw.equals("123")) {
    				JOptionPane.showMessageDialog(null, "Successful Login");
    				passLocked = false;
     
    			}
     
    			else {
    				JOptionPane.showMessageDialog(null,
    						"Incorrect input, please exit or re enter password ");
    			}
     
    		}
     
    	}
    }
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