Overload assignment operator C++ code example

Example 1: c++ operator overloading

// money.h -- define the prototype
class Money
{
   public:
      Money & operator += (const Money &rhs);
}

// money.cpp -- define the implementation
Money& Money :: operator += (const Money &rhs)
{
   // Yadda Yadda
  
   return *this;
}

Example 2: c++ overload operator

#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;
}

Example 3: Operator overloading in C++ Programming

#include <iostream>
using namespace std;

class Test
{
   private:
      int count;

   public:
       Test(): count(5){}

       void operator ++() 
       { 
          count = count+1; 
       }
       void Display() { cout<<"Count: "<<count; }
};

int main()
{
    Test t;
    // this calls "function void operator ++()" function
    ++t;    
    t.Display();
    return 0;
}

Example 4: operator overloading in c++

Box operator+(const Box&);

Example 5: c++ overload operator

#include <iostream>

class ExampleClass {
  public:
    ExampleClass() {}
  	ExampleClass(int ex) {
      example_ = 0;
    }
    int&       example()        { return example_; }
    const int& example() const  { return example_; }
  	//Overload the "+" Operator
  	ExampleClass operator+ (const ExampleClass& second_object_of_class) {
    	ExampleClass object_of_class;
    	object_of_class.example() = this -> example() + second_object_of_class.example();
    	return object_of_class;
  	}
  private:
  	int example_;
};

int main() {
  ExampleClass c1, c2;
  c1.example() = 1;
  c2.example() = 2;
  ExampleClass c3 = c1 + c2;
  //Calls operator+() of c1 with c2 as second_object_of_class
  //c3 gets set to object_of_class
  std::cout << c3.example();
}

Example 6: operator = overloading c++

inline bool operator==(const X& lhs, const X& rhs){ /* do actual comparison */ }
inline bool operator!=(const X& lhs, const X& rhs){ return !(lhs == rhs); }