Why does a variable need to be static in the finally-block

Question

I use Eclipse for programming and it tells me if want to output the "Input String"

Cannot make a static reference to the non-static field Input

Why has the variable to be static in the finally-block?

import java.util.Scanner;

public class NameSort {
    String Input;
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        try {
            System.out.println("Inupt some Text");
            while (sc.hasNextLine()){

                String Input = sc.nextLine();
                System.out.println(Input);
                if (Input.toLowerCase().equals("ende")) {
                    System.exit(0);
                    sc.close();
                }
            }

        } finally {
            if (sc != null)
            sc.close();
            System.out.print(Input);
        }
    }
}

Because the method is `static`. --- *FYI:* The `Input` local variable inside the `while` loop is entirely distinct from the `Input` field, since means that the field is never assigned, so will always be `null` in he `finally` block. — Andreas, Mar 25 '20 at 20:44
You have defined `Input` twice in two different scopes. Start by renaming either of those variables, and then maybe the answer will be clearer. — Kenneth K., Mar 25 '20 at 20:44
*FYI:* It's impossible for `sc` to be `null` in the `finally` block. — Andreas, Mar 25 '20 at 20:45
You shouldn't close a `Scanner` whose `InputStream` is `System.in`, even though the IDE tells you that you should. — Abra, Mar 25 '20 at 20:50

score 1 · Accepted Answer · answered Mar 25 '20 at 20:51

In Java, you can not use/call a non-static variable/method from a static method. Also, other than the following code, the rest of your code is useless:

import java.util.Scanner;

public class NameSort {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String input;
        System.out.println("Inupt some Text");
        while (!(input = sc.nextLine()).equals("ende")) {
            System.out.println(input);
        }
    }
}

A sample run:

Inupt some Text
hello
hello
hi
hi
ende

score 0 · Answer 2 · answered Mar 25 '20 at 20:44

0

This has nothing to do the finally block, in Java you can't access non-static members or methods from static methods.

You should make Input static if you want to access it from main.

answered Mar 25 '20 at 20:44

Adwait Kumar

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Why does a variable need to be static in the finally-block

2 Answers2