Trying to add a loop

[Joey McGee]

I'm trying to add a loop to my program to varify the meal code and if it's not valid, continue to prompt the user until it is. The meal code goes from 1-4. Below is my code so far:

//************************************************ 
// CateringCompany.java Author: Lawton 
//************************************************* 
import java.util.ArrayList; 
import java.util.Scanner;

public class CateringCompany 
{ 

	// instance variables 
	private ArrayList<Event> events = new ArrayList<Event>(); 

	public static void main(String[] args) 
	{ 
		
		Scanner scanner = new Scanner(System.in);

		System.out.println ("Enter the event number"); String eventNum = scanner.next();
		System.out.println ("Enter the host's name"); String hostName = scanner.next(); 
		System.out.println ("Enter the month of the event"); int month = scanner.nextInt();
		System.out.println ("Enter the day of the event"); int day = scanner.nextInt();
		System.out.println ("enter the year of the event"); int year = scanner.nextInt();	
		System.out.println ("Enter the number of guests"); int numOfGuests = scanner.nextInt();
		System.out.println ("Enter the meal code"); int mealCode = scanner.nextInt();
		
		//instance variables private
		Event event = new Event(eventNum, hostName, month, day, year, numOfGuests, mealCode);

		mealCode = 4;
		while (mealCode < 5){
		System.out.println ("Not a valid meal code"); 
		mealCode = mealCode - 5;
		}
		

	}

}

[Aj Prieto]

Just ask for mealCode again by adding:

mealCode = scanner.nextInt();

inside of your while loop.

What are the following lines for?

mealCode = 4;
mealCode = mealCode - 5;

Edit: Also, take a look at the boolean statement for you while loop, it's not doing what you think it's supposed to be doing.

[Greg Charles]

Having the loop at the end of the code isn't going to help you, and changing the user's choice (by subtracting 5) also seems unlikely to make the user happy. You should put the loop around where you ask the user for the meal code. Try to set up the loop so you will enter it once no matter what, enter it again if the input is invalid, and exit it if the input is valid.

[Rajdeep Biswas]

System.out.println ("Enter the meal code"); int mealCode = scanner.nextInt();  

You can replace this with:

boolean comeAgain = false;
do{
    System.out.println ("Enter the meal code");
    int mealCode = scanner.nextInt();
    if(mealCode < 5){
        System.out.println("Not a valid meal code! Should be 1-4 only.");
        comeAgain = true;
    }
    else {
        comeAgain = false;
    }
}(comeAgain);

PS: This is just a sample. You can optimize it further! Yes!!

[Campbell Ritchie]

I think you are mistaken trying to validate your meal code inside your main method. A main method is intended for starting your application, and you should restrict your methods to doing one thing. I think you should write yourself a utility class with such methods in. You can find an example here. You can write another method (in the same utility class) which validates the input is in the required range, (is it 1…5?) and prints an error message on screen. Those two methods call each other, so you are not duplicating code. Remember all members of utility classes are static.