Monday 12 September 2011

Constructor in java

Every class has at least one it's own constructort. Constructor creates a instance for the class. Constructor initiates (initialize) something related to the class's methods. Constructor is the method which name is same to the class. But there are many difference between the method (function) and the Constructor.
In this example we will see that how to to implement the constructor feature in a class. This program is using two classes. First class is another and second is the main class which name is Construct. In the Construct class two objects (a and b) are created by using the overloaded another Constructor by passing different arguments and calculated the are of the different rectangle by passing different values for the another constructor.
Here is the code of the program : 
class another{
  int x,y;
  another(int a, int b){
  x = a;
  y = b;
  }
  another(){
  }
  int area(){
  int ar = x*y;
  return(ar);
  }
}
public class Construct{
   public static void main(String[] args)
 {
 another b = new another();
 b.x = 2;
 b.y = 3;
 System.out.println("Area of rectangle : " + b.area());
 System.out.println("Value of y in another class : " + b.y);
 another a = new another(1,1);
 System.out.println("Area of rectangle : " + a.area());
 System.out.println("Value of x in another class : " + a.x);
 }
}
Output of the program : 
C:\chandan>javac Construct.java

C:\chandan>java Construct
Area of rectangle : 6
Value of x in another class : 3
Area of rectangle : 1
Value of x in another class : 1
Download this example.

No comments: