Tutorials

Assigning additional task to an operator is called operator overloading. It is one of the feature of compile time polymorphism. Operator overloading is an important concept in C++. It is a type of polymorphism in which an operator is overloaded to give user defined meaning to it. Overloaded operator is used to perform operation on user-defined data type.

C++ support two types of operator

1. Unary Operator
2. Binary Operator

	Syntax:
	class <class_name>
	{
	public: return_type operator sign(arguments)
		{
		}
	}

Note : .,::,sizeof(),&,: can not be inherited

A operator which apply on single operand is called as unary operator.

e.g: ++, --
WAP to overload ++ and --

#include<conio.h>
#include<iostream.h>
#include<math.h>
class Number{
  int a,b,c;
  public:
	Number(int i,int j,int k){
	  a=i;
	  b=j;
	  c=k;
	}
	void show(){
	   cout<<"\n a = "<<a;
	   cout<<"\n b = "<<b;
	   cout<<"\n c = "<<c;
	}
	void operator ++();
	void operator --();
};
void Number::operator ++(){
 a=abs(a);
 b=abs(b);
 c=abs(c);
}
void Number::operator --(){
 a=-abs(a);
 b=-abs(b);
 c=-abs(c);
}
void main()
{
 Number n(-5,6,-7);
 clrscr();
 cout<<"\nInitial values ";
 n.show();
 cout<<"\nAfter applying ++ operator ";
 n++;
 n.show();
 cout<<"\nAfter applying -- operator ";
 n--;
 n.show();
 getch();
}

O/P

Initial value
A=-5
B=6
C=-7
After applying ++ operator
A=-5
B=6
C=-7
After applying – operator
A=-5
B=6
C=-7

A operator which apply on two or more than two operands is called as Binary operator.

e.g: +,-,*,/
WAP to overload + and – operator

#include<iostream.h>
#include<conio.h>
class Complex{
  int real,img;
  public:
	 void get()
	 {
	  cout<<"\n Enter real and img value ";
	  cin>>real>>img;
	 }
	 void show()
	 {
	  cout<<"\n"<<real<<" + "<<img<<"i";
	 }
	 Complex operator +(Complex c2){
	 Complex temp;
	 temp.real=real+c2.real;
	 temp.img=img+c2.img;
	 return temp;
	}
	 Complex operator -(Complex c1){
	 Complex temp;
	 temp.real=real-c1.real;
	 temp.img=img-c1.img;
	 return temp;
	}
};
void main(){
Complex c1,c2,c3;
clrscr();
cout<<"\n First equation : ";
c1.get();
cout<<"\n Second equation : ";
c2.get();
c3=c1+c2;
c1.show();
c2.show();
cout<<"\n for Add   :";
c3.show();
cout<<"\n for Sub   :";
c3=c1-c2;
c3.show();
getch();
}

O/P

Enter quation :
First  real and img value
5
6
Second real and img value
7
6
5+6
6+7
For Add
12+12i
For Sub
-2+0i