What is Constructor

What is Constructor?

Constructor is special concept in every OOP language which is used to initialize values for the data members.
Constructors are automatically invoked whenever object or Instance for a class is created.
Constructor name should be same as className
Constructor should not have any return type.
     Syntax:
     className(){
      //block of code
     }

Basically we have 2 types of constructors:

Default constructor - Constructor having No arguments
Parameterized Constructor - Constructor having arguments

Constructor

Demo on Default Constructor:

public class DemoConstructor {
    String Bank;
    String Name;
    int Mobile;
   DemoConstructor() { // Default constructor

        System.out.println("This is constructor Block");
        Bank = "SBI";
        Name = "personName";
        Mobile = 1234567890;
    }

    public void accountType() {
        System.out.println("Print statement");
    }
    public static void main(String args[]) {
        DemoConstructor dc = new DemoConstructor(); //constructor automatically invoked
        System.out.println(dc.Bank);
        System.out.println(dc.Name);
        System.out.println(dc.Mobile);
        dc.accountType();
    }
}

--> Here, Whenever object created constructor is automatically invoked.

--> But accountType() is a method which will be called explicitly by using object.

Output:
This is constructor Block
SBI 
personName
1234567890 
Print statement

• Java compiler provides a default constructor if we don't provide any constructor in a class.

Constructor

Please comment below to feedback or ask questions.