What is the difference between a static and a non-static initialization code block

Question

My question is about one particular usage of static keyword. It is possible to use static keyword to cover a code block within a class which does not belong to

Answer 1

Uff! what is static initializer?

The static initializer is a static {} block of code inside java class, and run only one time before the constructor or main method is called.

OK! Tell me more...

• is a block of code static { ... } inside any java class. and executed by virtual machine when class is called.
• No return statements are supported.
• No arguments are supported.
• No this or super are supported.

Hmm where can I use it?

Can be used anywhere you feel ok :) that simple. But I see most of the time it is used when doing database connection, API init, Logging and etc.

Don't just bark! where is example?

package com.example.learnjava;

import java.util.ArrayList;

public class Fruit {

    static {
        System.out.println("Inside Static Initializer.");

        // fruits array
        ArrayList fruits = new ArrayList<>();
        fruits.add("Apple");
        fruits.add("Orange");
        fruits.add("Pear");

        // print fruits
        for (String fruit : fruits) {
            System.out.println(fruit);
        }
        System.out.println("End Static Initializer.\n");
    }

    public static void main(String[] args) {
        System.out.println("Inside Main Method.");
    }
}

Output???

Inside Static Initializer.

Apple

Orange

Pear

End Static Initializer.

Inside Main Method.

Hope this helps!