Repeating to the main menu upon a specific user input

Question

I am trying to create a simple program in java where the user can input some lines and then save it and then load the data from the saved file.

Currently, i have the basic outline of the program, but am stuck on the first stage where the user enters his data, then wishes to return to the main menu for another selection.

Code:

import java.io.*;
import java.util.*;

public class Datafile{

    private static Scanner input = new Scanner(System.in);

    public static void main(String[] args) throws IOException {
        BufferedWriter bw = new BufferedWriter(new FileWriter("C:\\Users\\Kence\\workspace\\Java 8 - Beyond the Basics - Working Files\\Practice Programs\\src\\Practice Data Edited",true));
        String data = null;
        String dataEntered = null;
        int menuChoice = printMenu();
        switch(menuChoice){
            case 1: 
                System.out.println("Please enter a line of data");
                dataEntered = input.nextLine();
                if(Integer.parseInt(dataEntered) == 0){
                    System.out.println("OK");
                    //printMenu(); <--- Qn 1. Where i am stuck
                    return;
                }else{
                    System.out.println(dataEntered);
                }
                //Why this does not recognize "quit" when entered
                /*if(dataEntered == "quit"){   <--- Qn2. Where i am stuck
                    System.out.println("OK");
                }else{
                    System.out.println("Error");
                }*/
                data += dataEntered;
                System.out.println("Data entered.Please enter the next line of data or press quit to exit back to the main menu.");

                break;

            case 2:
                System.out.println("2 Entered");
                break;
            case 3:
                System.out.println("3 Entered");
                break;
            case 4:
                System.out.println("4 Entered");
                break;
        }

        input.close();
    }



    public static void printStars(){
        for(int i = 0; i<66 ; i++){
            System.out.print("*");
        }
        System.out.println();
    }

    public static int printMenu(){

        printStars();
        System.out.println("System Started");
        printStars();
        System.out.println("Enter 1 to input a new line of data");
        System.out.println("Enter 2 to list all data");
        System.out.println("Enter 3 to save existing data");
        System.out.println("Enter 4 to load data");
        printStars();
        return Integer.parseInt(input.nextLine());
    }

}

QN 1 In the code example above, when the user enters 0, the i can run printMenu(), but am unable to take any further action after that. I would like to be able to select the options 2,3 or 4 after the user enters 0.

Edit: printMenu works fine on the initial start-up, it's after i enter 1,input data, then press 0, that the new printMenu() does not work as i'm not actually testing the input with a switch statement. I can't figure out a way to run printMenu() again at this point without nesting another switch statement, and another switch statement after that and so on..

Qn2.

When i enter quit, the program does not output "OK", but outputs ERROR instead. I don't understand why this is happening as i am comparing the input (which is a string) with the string "quit", yet somehow the program does not recognise both strings as equals?

I would appreciate any clarifications and advice.

Thanks!

Not sure what's Qn1 about.. but [Qn2's solution](http://stackoverflow.com/questions/513832/how-do-i-compare-strings-in-java). — almightyGOSU, Jul 18 '15 at 12:17
@Gosu Hi Gosu, thanks for the solution. For Qn1. i just want to rerun printMenu() so that i can enter 2,3, or 4 as a menu choice and have it work. However, currently, when i enter 0, it only runs printMenu(), and does not register any further input. — Kenneth .J, Jul 18 '15 at 12:39

deezy · Answer 1 · 2015-07-18T13:18:17.997

0

Qn1: Here's another way to retrieve the input, hopefully it will solve the problem:

public static int printMenu(){
    ...
    intInput = input.nextInt();
    input.nextLine();
    return intInput;
}

Qn2: The == comparator is not used for strings. Try this instead:

if(dataEntered.equalsIgnoreCase("quit")) {
    ...
}

edited Jul 18 '15 at 13:18

answered Jul 18 '15 at 13:05

deezy

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Repeating to the main menu upon a specific user input

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