Overload prefix ++ for Point : overload unary operator « Operator Overloading « C++ Tutorial

Home
C++ Tutorial
1.Language Basics
2.Data Types
3.Operators statements
4.Array
5.Development
6.Exceptions
7.Function
8.Structure
9.Class
10.Operator Overloading
11.Pointer
12.File Stream
13.template
14.STL Introduction
15.string
16.vector
17.list
18.bitset
19.set multiset
20.valarray
21.queue stack
22.deque
23.map multimap
24.STL Algorithms Modifying sequence operations
25.STL Algorithms Non modifying sequence operations
26.STL Algorithms Binary search
27.STL Algorithms Sorting
28.STL Algorithms Merge
29.STL Algorithms Min Max
30.STL Algorithms Iterator
31.STL Algorithms Heap
32.STL Algorithms Helper
C / ANSI-C
C Tutorial
C++
Visual C++ .NET
C++ Tutorial » Operator Overloading » overload unary operator 
10.8.6.Overload prefix ++ for Point
#include <iostream>
using namespace std;

class Point {
  int x, y;
public:
  Point() {} // needed to construct temporaries
  Point(int px, int py) {
    x = px;
    y = py;
  }

  void show() {
    cout << x << " ";
    cout << y << "\n";
  }

  Point operator+(Point op2);
  Point operator-(Point op2);
  Point operator=(Point op2);
  Point operator++();
};

// Overload + for Point.
Point Point::operator+(Point op2)
{
  Point temp;

  temp.x = op2.x + x;
  temp.y = op2.y + y;

  return temp;
}

// Overload - for Point.
Point Point::operator-(Point op2)
{
  Point temp;

  // notice order of operands
  temp.x = x - op2.x;
  temp.y = y - op2.y;

  return temp;
}

// Overload asignment for Point.
Point Point::operator=(Point op2)
{
  x = op2.x;
  y = op2.y;

  return *this// i.e., return object that generated call
}

// Overload prefix ++ for Point.
Point Point::operator++()
{
  x++;
  y++;

  return *this;
}

int main()
{
  Point ob1(1020), ob2530), ob3(9090);

  ob1.show();
  ob2.show();

  ++ob1;
  ob1.show()// displays 11 21

  ob2 = ++ob1;
  ob1.show()// displays 12 22
  ob2.show()// displays 12 22

  ob1 = ob2 = ob3; // multiple assignment
  ob1.show()// displays 90 90
  ob2.show()// displays 90 90

  return 0;
}
10 20
5 30
11 21
12 22
12 22
90 90
90 90
10.8.overload unary operator
10.8.1.Overloading ++
10.8.2.Overloading the increment operator
10.8.3.Overload the ++ unary operator
10.8.4.Overload the postfix version of ++.
10.8.5.Demonstrate prefix and postfix ++
10.8.6.Overload prefix ++ for Point
10.8.7.Lvalues and rvalues
10.8.8.Using a Friend to Overload ++ or – –
www.java2java.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.