Overloading increment and decrement operators in C++

November 1, 2021

Overloading ++/- -operators

Operator overloading enhances the power of extensibility of c++
It provides new meaning to most of the cplusplus operators
As a result, the operator that is overloaded is capable to provide special meaning to the user-defined data types as well.

We can overload unary operators like ++,–etc to directly manipulate the object of a class

Syntax:

return_type::operator increment/decrementoperator _symbol(parameters)
{
// function definition
}

Here operator is a keyword, increment/decrement operator symbol is the operator to be overloaded

Overloading Prefix increment (++) operator

#include<iostream>
using namespace std;
class test
{
   private:
   int i;
   public:
   test(): i(0) { }//initialise data memeber

   void operator ++() 
  { 
     ++i; 
  }

  void display() 
  { 
     cout << "i:" << i << "\t";
  }
};

int main()
{
  test t;

  // Displays the value of data member i for object t
  t.display();

  // Invoke the  operator function void operator ++( )
  ++t; 

  // Displays the value of data member i for object t
  t.display();
  return 0;
}

Output

i:0	i:1

Initially, when test t is declared, the value of data member i for object test t is 0 (constructor initializes i to 0).
When ++ operator is called on the object t, operator function void operator++( ) is invoked which increments the value of data member i to 1.

Overloading increment and decrement operators in C++

Overloading ++/- -operators

Syntax:

Overloading Prefix increment (++) operator

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