The Initializer Block in Java

The Initializer block is used to declare constructors’ common parts. Let us see an example −

Example

 Live Demo

import java.io.*;
public class Demo{
   {
      System.out.println("The common constructor has been invoked");
   }
   public Demo(){
      System.out.println("The default constructor has been invoked");
   }
   public Demo(int x){
      System.out.println("The parametrized constructor has been invoked");
   }
   public static void main(String arr[]){
      Demo my_obj_1, my_obj_2;
      System.out.println("The Demo objects have been created.");
      my_obj_1 = new Demo();
      my_obj_2 = new Demo(89);
   }
}

Output

The Demo objects have been created.
The common constructor has been invoked
The default constructor has been invoked
The common constructor has been invoked
The parametrized constructor has been invoked

A class named Demo contains a constructor without a parameter, a parameterized constructor, and the main function. Inside the main function, an instance of the Demo class is created, one with parameter, and one without parameter.