Constructor

• Constructor name should be the class name.
• Constructor is a special method used to initialize the value for instance variable when the object created.
• when we create an object contructor will automatically run.
• we cannot manually run/call the contructor.
• this is the java keyword.

Costructor types:
1.Default constructor
2.No-Argument Constructor
3.Parameterized constructor

Example:
class Bank {

int accountNo;
String name;
int balance;

Bank(int accountNo, String name , int balance)
{
    this.accountNo = accountNo;
    this.name = name;
    this.balance = balance;
}

public static void main(String[] args)
{

    Bank accholder = new Bank(101,"kumar",1000);
    System.out.println(accholder.accountNo);//101

    Bank accholder1 = new Bank(102,"hari",1000);
    System.out.println(accholder1.accountNo); //102

}

}

• What is the purpose of constructor?
  Used to initial the values for instance variables at the object creation. By using *this * keyword, we can access/assign values to the instance varaiable inside constructor. this refers to current object only. So this keyword is used to differentiate instance variables from local variables.

• what is constructor over loading?
  while we are creating more than one contructor, arguments will differ for each contructors.
  example:
  public class Payilagam {

  String name;
  String email;
  String password;

  Payilagam(String name, String email, String password)
  {
  this.name = name;
  this.email = email;
  this.password = password;
  }

  Payilagam( String email, String password)
  {

  this.email = email;
  this.password = password;
  

  }

  public static void main(String[] args)
  {
  Payilagam user1 = new Payilagam("kumar","abc.com","kumar@123");
  System.out.println(user1);

  Payilagam user2 = new Payilagam("abc.com","kumar@123");
  System.out.println(user2);
  

  }

}