what is a constructor and types of constructor

Constructor

• Constructor is a special,method which is used to initialize the object at the time of creation.
• Constructor is a member function of class and initializes objects of a class.

Characteristics of constructor

• Constructor does not have return type,not even void.
• In constructor the method name is same as the class name.
• Constructor can be overloaded.
• Constructor  can invoke automatically.

Types of constructor

1.Default Constructor:-

• If no constructor are defined for a class,the compiler automatically generate default constructor.
• Default constructor don't have parameters.

2. Parameterized Constructor:-

• If any constructor which have parameters then it is called parameterized constructor.
• Constructor is also overloaded (java allows overloading of constructor as well as methods).

//Syntax for Default and Parameterized constructor

public DemoConstructor

{

       int num1=45;               // Defining Default Constructor 

       int num2=65;

}

public DemoConstructor(int x,int y)↑・Ҝ.↑↑↑

{

      num1=x;                   //Defining Parameterized Constructor

      num2=y;

}

DemoConstructor dc=new DemoConstructor();              //Default Constructor Object Creation

DemoConstructor dc1=new DemoConstructor(20,30);  //Parameterized Constructor Object Creation