C++ Tutorial Home Page

C++ Operator Overloading

What is operator overloading
Rules for overloading Operators
Operator Overloading restrictions
List of operators that cannot be overloaded.
Overloading Unary operator
Overloading increment operator(++)
Overloading decrement operator(–)
Overloading unary operator(-)
Overloading increment operator(++) postfix
Overloading decrement operator(–) postfix
Overloading increment operator (++) with friend function
Overloading increment operator (–) with friend function
Increment the time using ++
Decrement the time using ++
Overloading Binary operator(+,-,*,/,%)
Add two object using “+” operator with friend function
Overloading “-” operator
Overloading “*” operator
Overloading “/” operator
Overloading “%” operator
overloading all (+,-,*,/,%)
Overloading “+” operator with friend function
class distance (feet,inches) with “+” operator
class distance (feet,inches) with “+” operator with friend function
class distance (km,m) with “+” operator
class distance (km,m) with “+” operator with friend function
class distance (m,cm) with “+” operator
class distance (m,cm) with “+” operator with friend function
class distance (km,m,cm) with “+” operator
class distance (km,m,cm) with “+” operator with friend function
class distance (km,m,cm,mm) with “+” operator
class distance (km,m,cm,mm) with “+” operator with friend function
class time(hh,mm,ss) with “+” operator
class time(hh,mm,ss) with “+” operator with friend function
class complex(real,ing) with “+” operator
class complex(real,ing) with “+” operator with friend function
class string(str) with “+” operator
class string(str) with “+” operator with friend function
overloading “+=” operator

C++:Overloading relational operator (<,>,<=,>=,==,!=)

Overloading relational operator(<,>,<=,>=,==,!=)

Example:1
compare two objects using overloaded operator “<“.

// to overload < operator
//  to compare the values of two objects
#include<iostream>
#include<conio.h>
using namespace std;
class sample
{
	int a;
public:
	sample();
	sample(int n);
	void get();
	void disp();
	int operator<(sample s);
};
sample::sample()
{
	a=0;
}
sample::sample(int n)
{
	a=n;
}
void sample::get()
{
	cout<<"Enter the value of a ";
	cin>>a;
}
void sample::disp()
{
	cout<<"a= "<<a<<endl;
}

int sample::operator<(sample s)
{
	return(a<s.a);
	/*
	if (a<s.a)
	return(1);
	else
	return(0);
	*/
}
int main()
{
  sample s1,s2;
  s1.get();s2.get();
  s1.disp();s2.disp();
  int t;
  t=s1<s2;  //t=s1.operator<(s2);
  if (t==1)
  cout<<"the object s1 is less than object s2"<<endl;
  else
  cout<<"the object s1 is not less than object s2"<<endl;
  getch();
  return(0);
}

Output:

Enter the value of a 10
Enter the value of a 52
a= 10
a= 52
the object s1 is less than object s2

Example:2
compare two objects using overloaded operator “<=“.

// to overload <= operator
//  to compare the values of two objects
#include<iostream>
#include<conio.h>
using namespace std;
class sample
{
     int a;
public:
     sample();
     sample(int n);
     void get();
     void disp();
     int operator<=(sample s);
};
sample::sample()
{
     a=0;
}
sample::sample(int n)
{
     a=n;
}
void sample::get()
{
     cout<<"Enter the value of a ";
     cin>>a;
}
void sample::disp()
{
     cout<<"a= "<<a<<endl;
}

int sample::operator<=(sample s)
{
     return(a<=s.a);
     /*
     if (a<=s.a)
     return(1);
     else
     return(0);
     */
}
int main()
{
  sample s1,s2;
  s1.get();s2.get();
  s1.disp();s2.disp();
  int t;
  t=s1<=s2;  //t=s1.operator<=(s2);
  if (t==1)
  cout<<"the object s1 is less than or equal to object s2"<<endl;
  else
  cout<<"the object s1 is not less than or equal to object s2"<<endl;
  getch();
  return(0);
}

Output:

Enter the value of a 25
Enter the value of a 63
a= 25
a= 63
the object s1 is less than or equal to object s2

Example:3
compare two objects using overloaded operator “>“.

// to overload > operator
//  to compare the values of two objects
#include<iostream>
#include<conio.h>
using namespace std;
class sample
{
     int a;
public:
     sample();
     sample(int n);
     void get();
     void disp();
     int operator>(sample s);
};
sample::sample()
{
     a=0;
}
sample::sample(int n)
{
     a=n;
}
void sample::get()
{
     cout<<"Enter the value of a ";
     cin>>a;
}
void sample::disp()
{
     cout<<"a= "<<a<<endl;
}

int sample::operator>(sample s)
{
     return(a>s.a);
     /*
     if (a>s.a)
     return(1);
     else
     return(0);
     */
}
int main()
{
  sample s1,s2;
  s1.get();s2.get();
  s1.disp();s2.disp();
  int t;
  t=s1>s2;  //t=s1.operator>(s2);
  if (t==1)
  cout<<"the object s1 is greater than object s2"<<endl;
  else
  cout<<"the object s1 is not greater than object s2"<<endl;
  getch();
  return(0);
}

Output:

Enter the value of a 25
Enter the value of a 6
a= 25
a= 6
the object s1 is greater than object s2