Java Skipping switch statement using getter as expression-CodePudding

Hey Sorry for the what for you guys must seem like a stupid question but I've been stuck on this for a while now, im using a getter from a different class as the switch expression in another class, my program keeps skipping the entire switch alltogether.

Thank you for your time!

First class


public class InputRequests {
    public int loginRole;


    public void loginChoice(){
        Scanner login = new Scanner(System.in);
        loginRole = login.nextInt();
    }

    public int getLoginRole() {
        return loginRole;
    }
}

Second class

public class Menus {

    public void loginChoiceCase() {
        InputRequests inp = new InputRequests();
        switch (inp.getLoginRole()) {
            case 1 -> System.out.println("test");
            case 2 -> System.out.println("tested");
            case 3 -> System.exit(1);
        }
    }
}

main

public class Main {
    public static void main(String[] args) {
        Printblocks print = new Printblocks();
        InputRequests input = new InputRequests();
        Menus menu = new Menus();
        print.firstMenu();
        input.loginChoice();
        menu.loginChoiceCase();
        System.out.println(input.getLoginRole());
    }
}

The first menu print is just a pintblock without anything else, when running the program I do get the int I enter back.

CodePudding user response：

Your program isn't skipping over the switch statement. Look at the Menus.loginChoiceCase() method. It's creating a new instance of InputRequests. Which means inp.getLoginRole() is null, and your switch statement doesn't have a default case to catch nulls.

Add a default case to the switch statement

default -> System.out.println("Null");

Ideally what you would want to do is have your loginChoiceCase() method take in an int, and then use that in you case statement. With loginChoiceCase() able to take in an int you can then use your getter. Like below.

InputRequests

public class InputRequests {
public int loginRole;


public void loginChoice(){
    Scanner login = new Scanner(System.in);
    loginRole = login.nextInt();
}

public int getLoginRole() {
    return loginRole;
}
}

Menus

public class Menus {

public void loginChoiceCase(int choice) {
    switch (choice) {
        case 1 : System.out.println("test");
        case 2 : System.out.println("tested");
        case 3 : System.exit(1);
        default : System.out.println("Null");
    }
}
}

Main

public class Main {
public static void main(String[] args) {
    Printblocks print = new Printblocks();
    InputRequests input = new InputRequests();
    Menus menu = new Menus();
    print.firstMenu();
    menu.loginChoiceCase(input.getLoginRole);
    System.out.println(input.getLoginRole());
}
}

CodePudding user response：

You need to remove this line because this is a different object from what you declared in the main method

public class Menus {

    public void loginChoiceCase() {
        InputRequests inp = new InputRequests(); <--- delete this line
        switch (inp.getLoginRole()) {
            case 1 -> System.out.println("test");
            case 2 -> System.out.println("tested");
            case 3 -> System.exit(1);
        }
    }
}

Explanation: why this happened?

Because the object you declared in the loginChoiceCase method has didn't store the value from the user console and the value of loginRole the default which is zero and you don't have a menu with zero case.