Thread: Something about this while statement that I can't seem to figure out

Hello --

I want to preface this by saying I'm not a professional programmer. I really enjoy learning programming/Java though, and have some experience with programming going back to my high school days, but it's been a LOOOOONG time since going back to it (I'm in my 50's now....)

I'm trying to put together a basic contacts application myself. I thought it would be a good way to try to learn the language, gradually building it as I learn more and more (Eventually I'd like to put this on my Linux computer, rather than try to find an app online).

I have the Head First Java Book, and it's really a good one; clear explanations and good examples.

For now, I have a while statement, in the my MainMenu class, which has an addContact() method that takes in string information, and populates the variables of my Contact class, then adds it to a contactList ArrayList. Here's the code for the MainMenu class:

 
import java.util.*;
 
public class MainMenu {// open class
	ArrayList<Contact>contactList=new ArrayList<Contact>();
	MenuHelper helper= new MenuHelper();
 
 
		public void showMenu(String mainMenuChoice) {//open method
 
				while (Integer.parseInt(mainMenuChoice)!=4) {//open while loop
				System.out.println("Main Menu:");
				System.out.println();
				System.out.println("1: Add Contact");
				System.out.println("2: Edit/Delete Contact");
				System.out.println("3: Search For Contact");
				System.out.println("4: Quit Application");
				System.out.println();
 
		mainMenuChoice = helper.getUserInput("Enter Choice:");
			if (Integer.parseInt(mainMenuChoice)==1) {//open if loop for choices
				addContact();
				}//close if loop
		}//close while loop
	}//close showMenu() method
 
 
		public void addContact() {//open method
			Scanner myScanner=new Scanner(System.in);
 
			String contactName="";
			String address1="";
			String address2="";
			String state="";
			String city="";
			String zipCode="";
			String phoneNumber="";
			String email="";
 
			System.out.println();
			System.out.println("Enter STOP to return to Main Menu");
			System.out.println();
 
			while ((!contactName.equals("STOP"))||(!address1.equals("STOP"))||
				(!address2.equals("STOP"))||(!state.equals("STOP"))||
				(!zipCode.equals("STOP"))||(!phoneNumber.equals("STOP"))||
				(!email.equals("STOP")) ) { 
 
			Contact contact=new Contact();
 
			System.out.print("Contact name: ");
			contactName=myScanner.nextLine();
			System.out.println();
			System.out.print("Address 1: ");
			address1=myScanner.nextLine();
			System.out.println();
			System.out.print("Address 2: ");
			address2=myScanner.nextLine();
			System.out.println();
			System.out.print("City: ");
			city=myScanner.nextLine();
			System.out.println();
			System.out.print("State: ");
			state=myScanner.nextLine();
			System.out.println();
			System.out.print("Zip Code: ");
			zipCode=myScanner.nextLine();
			System.out.println();
			System.out.print("Phone Number: ");
			phoneNumber=myScanner.nextLine();
			System.out.println();
			System.out.print("Email: ");
			email=myScanner.nextLine();
			System.out.println();
 
 
			contact.setName(contactName);
			contact.setAddress1(address1);
			contact.setAddress2(address2);
			contact.setState(state);
			contact.setCity(city);
			contact.setZip(zipCode);
 
			contactList.add(contact);
 
			System.out.println();
			System.out.println(contactName);
			System.out.println(contactList.get(0).getName());
 
			}//close while
		}//close method
	}//close class

Here's a sample output:

 
Main Menu:
 
1: Add Contact
2: Edit/Delete Contact
3: Search For Contact
4: Quit Application
 
Enter Choice:1
 
Enter STOP to return to Main Menu
 
Contact name: Name
 
Address 1: Street
 
Address 2: Street2
 
City: STOP
 
State: STOP
 
Zip Code: STOP
 
Phone Number: STOP
 
Email: STOP
 
 
Name
Name
Contact name: Name 2
 
Address 1: Street2
 
Address 2: Street 
 
City: STOP
 
State: STOP
 
Zip Code: STOP
 
Phone Number: STOP
 
Email: STOP
 
 
Name 2
Name
Contact name:

For the life of me I can't seem to figure why the while statement won't break out of the loop even after I entered the first contact -- at the very least it should break out of the loop after the first contact, when the "STOP" condition is met when it goes back to the top of the "while" loop, but it doesn't.

It's probably right in front of my face, yet I can't see why.

So -- is these even a case where a WHILE loop is even appropriate? But it's the only thing that can continuously loop to enter a theoretically limitless number of contacts to the ArrayList. So do I need to set some other condition in the while loop to get it to loop, and then an individual IF statement for each instance variable to see if "STOP" has been entered, then break out of the loop?

If you're wondering about the two input methods I'm using, I came across the Scanner() method on another blog/site, and thought I'd use it. The other method in the showMenu() method is some ready bake code from one of the HFJ chapters.

The println() methods at the end of while loop are there for me, as a way of trying to see what's going on. I don't plan on keeping them.

And, as I said before, please forgive any mistakes in here re: coding etiquette/standards. I'm still trying to learn them, based on what I've read in the code examples so far in the HFJ book, but I may have made mistakes, as well as the possibility that the code isn't as lean as it could be.

Any advice will be welcome.

A while loop exits when its boolean expression is false.
When are all the conditions tested in the while loop false?
The OR operator means that if any one of the sub expressions is true the expression is true.
(false || false || false || true) is true

With the AND operator, all the sub expressions need to be true for the full expression to be true:
(true && true && true && false) is false

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--- Update ---

Also posted here: https://coderanch.com/t/749462/java/...operly#3480334

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