Inherited Constructor Calls Parent Constructor by Default in Java

In this article, we will learn about constructors in Java. Constructors initialize objects when they are created. We will also see how the parent constructor is called in inheritance.

Problem Statement

We will demonstrate possible approaches to show how the inherited constructor calls the parent constructor by default.

Different approaches

The following are the different approaches to show how the inherited constructor calls the parent constructor by default?

• Demonstrating inheritance properties
  

• Inheriting constructors in child classes

• Using constructors and print methods in inherited classes
  

Demonstrating inheritance properties approach

Input 

No input is required from the user. The program automatically runs based on predefined constructor calls.

Output

How Are You Brother/Sister!?
We Are From Tutorialspoint

Steps for the demonstrating inheritance properties approach

The following are the steps for the inheritance properties approach?

• Create a parent class Programmingwith2023 with two constructors, one with no parameters and one with two integer parameters.
  
• Create a child class RDDARB that extends Programmingwith2023.
  
• In the child class, call the parent constructor using super() and print messages to show constructor calls.

Example 1

The following is an example of a Java program for the inheritance properties approach?

class Programmingwith2023 {
   public Programmingwith2023 (){
      System.out.println("Hey! I Am A Coder....");
   }
   public Programmingwith2023 (int i, int j){
      System.out.println("How Are You Brother/Sister!?");
   }
}
class RDDARB extends Programmingwith2023 {
   public RDDARB(){
      super(10, 20);
      System.out.println("We Are From Tutorialspoint");
   }
   public RDDARB (int i, int j){
      System.out.println("RDDARB + +");
   }
}
public class Rudra {
   public static void main(String[] args){
      RDDARB obj = new RDDARB();
   }
}

Output

How Are You Brother/Sister!?
We Are From Tutorialspoint

Inheriting constructors in child classes approach

Input

No input is required from the user. The constructors are called when objects are created.

output

I am an Indian
...........@...........
I am an Indian
I live in West Bengal

Steps for inheriting constructors in child classes approach

The following are the steps for inheriting constructors in child classes approach?

• Create a parent class with a constructor that prints a message.
  
• Create a child class that extends the parent class.
  
• When the child class constructor is called, the parent class constructor runs first.
  
• Print messages from both the parent and child constructors.

Example 2

The following is an example of a Java program in which constructors from the parent class are inherited and invoked in the child class?

public class RDDARB {
	public static void main(String[] a){
		new child();
		new parent();
	}
}
class parent {
	parent(){
		System.out.println("I am an Indian");
	}
}
class child extends parent {
	child(){
		System.out.println("..................");
	}
}

Output

I am an Indian
..................
I am an Indian

Using constructors and print methods in inherited classes approach

Input

No input is required from the user. The program runs predefined constructors, including one with a parameter (2001).

Output

I am an Indian
...........@...........
I am an Indian
I live in West Bengal

Steps for using Constructors and Print Methods in Inherited Classes Approach

The following are the steps for using constructors and print methods in inherited classes approach ?

• Create a parent class with a constructor that prints a message.
  
• Create a child class that extends the parent class and adds its own constructor.
  
• Use multiple constructors in the child class, including one with parameters.
  
• The parent constructor runs first, followed by the child's constructor.
  
• Print messages from both constructors, with or without parameters.

Example 3

The following is an example of using constructors and print methods in inherited classes approach?

public class indiancode {
	public static void main(String[] a) {
		new child();
		new child(2001);
	}
}
class parent {
	parent() {
		System.out.println("I am an Indian");
	}
}
class child extends parent {
	child() {
		System.out.println("...........@...........");
	}
	child(int x) {
		System.out.println("I live in West Bengal");
	}
}

Output

I am an Indian
...........@...........
I am an Indian
I live in West Bengal