Lecture Notes For Web Application using Java 
                                  VarunNalluri 
                                   CS 4VN 
                              Computer Science Department 
                              Illinois Institute of Technology 
                                Chicago, Illinois 60616 
                                vnalluri@hawk.iit.edu 
         Week :6Constructors 
          "Constructor is and initialization routine having same name as class name, which called automatically at 
         the time of object creation." In object-oriented programming, a constructor  in a class is a special type 
         of subroutine called at the creation of an object. It prepares the new object for use, often accepting 
         parameters which the constructor uses to set any member variables required when the object is first 
         created. It is called a constructor because it constructs the values of data members of the class. 
         The purpose of the constructor is initialization followed by instantiation.  
         Constructor Rules:  
         a) The name of constructor must be same as class name.  
         b) The only applicable modifiers for the constructors are:  
          
         i) Public ii) protected iii) no accessibility iv) private 
         c) The constructor must not return any type not even void. 
          
         Example:  
         Public class Box{ 
         Int width;  
         Int height;  
         Int depth;  
         public Box(int w, int h, int d){  
         width = w;  
         height = h;  
         depth = d;  
         }  
         }  
         Box b = new Box(1,2,3); //Instantiation  
          
                                                                  
               Lecture Notes For Web Application using Java 
                                  VarunNalluri 
                                   CS 4VN 
                              Computer Science Department 
                              Illinois Institute of Technology 
                                Chicago, Illinois 60616 
                                vnalluri@hawk.iit.edu 
         Constructors are either Default constructors or Parameterized constructors:  
         Reference type  
         Primitive type  
         Explicit default constructors  
         Implicit default constructor  
         Parameterized construcotrs 
         Default constructors  
         Constructors