• What is a constructor?
  • A constructor is a method which has the same name as the class.

Employee Emp = new Employee() 

// new Employee() => will trigger the constructor call

class Employee{

Employee() {}

}

• Key Feature of a constructor:

  1. Same name as class
  2. Void return type
  3. If you are not defining the constructor : the internal default constructor is called.

• Purpose of consturcotr:

  1. To create an object
  2. Reuse the code

  Every time we are creating an object : we are sort of reusing the code to initialize something
  
  

  1. Set some default

• Types of constructor

  1. Non parameterized constructor

  2. Parameterized constructor

     1. Constructor overloading is also possible

  3. Copy constructor

     class Account{
     name, balance;
     
     Account(name, balance)
     {
     this.name = name;
     this.balance = balance;
     }
     
     Account (Account account) {
     Account(Account.getName(), Account.getBalance());
     }
     
     getName() 
     {...}
     
     getBalance()
     {...} 
     
     main()
     {
     Account obj1 = new Account("Raj", 1000);
     Account obj2 = new Account(obj1);  // this will put value from obj1
     
     }
     

1. Can a constructor call another constructor?

   Yes We can call it. (Like in the example of copy constructor we just saw)

2. Can a constructor be overloaded?

   Yes. ( same constructor name, accepting: different number of parameters.. and different types of parameters)

Note that whenever a constructor is called : it is stored in heap memory

Whenever the reference to the heap memory is gone:

the garbage collector clears that heap mamory

( this is not there in c++;

we would need the keyword delete for that.)