C++ LANGUAGE OPERATORS OVERLOADING

COMPUTER LANGUAGES HTML,C,C++.JAVA,.NET AND MULTIMEDIA basics and programs click home button

C++ LANGUAGE OPERATORS OVERLOADING

Operators Overloading in C++ 

You can redefine or overload most of the built-in operators available 
in C++. Thus, a programmer can use operators with user-defined types as well. 
Overloaded operators are functions with special names the keyword 
operator followed by the symbol for the operator being defined. 
Like any other function, an overloaded operator has a return type 
and a parameter list. 

Box operator+(const Box&); 

Declares the addition operator that can be used to 
add two Box objects and returns final Box object. 

Most overloaded operators may be defined as ordinary 
non-member functions or as class member functions. 
In case we define above 

function as non-member function of a class then
 we would have to pass two arguments for each operand as follows: 

Box operator+(const Box&, const Box&); 

Following is the example to show the concept of operator 
over loading using a member function. Here an object is 
passed as an argument whose properties will be accessed 
using this object, the object which will call this operator 
can be accessed using this operator as explained below: 

#include <iostream> 

using namespace std; 
 
class Box 
{ 
   public: 
 
      double getVolume(void) 
      { 
         return length * breadth * height; 
      } 
      void setLength( double len ) 
      { 
          length = len; 
      } 
 
      void setBreadth( double bre ) 
      { 
          breadth = bre; 
      } 
 
      void setHeight( double hei ) 
      { 
          height = hei; 
      } 
      // Overload + operator to add two Box objects. 
      Box operator+(const Box& b) 
      { 
         Box box; 
         box.length = this->length + b.length; 
         box.breadth = this->breadth + b.breadth; 
         box.height = this->height + b.height; 
         return box; 
      } 
   private: 
      double length;      // Length of a box 
      double breadth;     // Breadth of a box 
      double height;      // Height of a box 
}; 
// Main function for the program 
int main( ) 
{ 
   Box Box1;                // Declare Box1 of type Box 
   Box Box2;                // Declare Box2 of type Box 
   Box Box3;                // Declare Box3 of type Box 
   double volume = 0.0;     // Store the volume of a box here 
  
   // box 1 specification 
   Box1.setLength(6.0);  
   Box1.setBreadth(7.0);  
   Box1.setHeight(5.0); 
  
   // box 2 specification 
   Box2.setLength(12.0);  
   Box2.setBreadth(13.0);  
   Box2.setHeight(10.0); 
  
   // volume of box 1 
   volume = Box1.getVolume(); 
   cout << "Volume of Box1 : " << volume <<endl; 
  
   // volume of box 2 
   volume = Box2.getVolume(); 
   cout << "Volume of Box2 : " << volume <<endl; 
 
   // Add two object as follows: 
   Box3 = Box1 + Box2; 
 
   // volume of box 3 
   volume = Box3.getVolume(); 
   cout << "Volume of Box3 : " << volume <<endl; 
 
   return 0; 
} 

When the above code is compiled and executed, 
it produces the following result: 

Volume of Box1 : 210 
Volume of Box2 : 1560 
Volume of Box3 : 5400