---
title: "Pure virtual function C++"  
description: "In this blog, I’m explaining about Pure virtual function in c++A pure virtual function is a function that has the notation “=0” in the declaration  of"  
author: "priyanka kushwaha"  
published: 2015-01-30  
updated: 2015-01-30  
canonical: https://www.mindstick.com/blog/749/pure-virtual-function-c-plus-plus  
category: "visual c++"  
tags: [".net"]  
reading_time: 1 minute  

---

# Pure virtual function C++

In this [blog](https://www.mindstick.com/articles/12705/myths-and-misconception-about-blog), I’m explaining about Pure [virtual function](https://www.mindstick.com/forum/161768/what-is-virtual-function-and-why-is-it-used-with-example) in [c++](https://www.mindstick.com/blog/745/array-in-c-plus-plus)

A pure virtual function is a function that has the notation “=0” in the declaration of that function.

##### Example

```
#include "stdafx.h"#include <iostream>#include <string> using namespace System;using namespace std;class VirtualClass{public:            virtual void display(int )=0;// a pure virtual function //There is not function body};class  overload{public:             overload();             int add(int a,int b)             {                         return a+b;             }             float add(float a,int b)             {                         return a+b;             }             void display(float res)             {                         cout<<res;             } ~ overload(); private: };class DriveClass:overload{public:void add(char str[30],char str1[30]){                        char result[100];                        int j=0;                for(int i=0;str[i]!='\0';i++)                        {                                    result[j]=str[i];                                    j++;                        }                        for(int i=0;str1[i]!='\0';i++)                        {                                    result[j]=str1[i];                                    j++;                        }                        for(int i=0;result[i]!='\0';i++)                                    cout<<result[i];                                                }void  display(int res)             {                         cout<<res;             }            DriveClass();            ~DriveClass();private:}; DriveClass::DriveClass(){} DriveClass::~DriveClass(){}  overload:: overload(){}overload::~ overload(){} int main(array<System::String ^> ^args){            overload obj;            DriveClass Driobj;            while (true)            {                        int exec;                        cout<<"\n1)For Integer Addition\n";                        cout<<"2)For Float Addition\n";                        cout<<"3)for String Additon";            cout<<"4)exit\n";                        cout<<"Enter any option";           cin>>exec;                         switch (exec)                         {                         case 1:                                     float a,b,res;                                     cout<<"Enter two nos.";                                     cin>>a>>b;                                     res=obj.add(a,b);                                     obj.display(res);                                    break;                         case 2:                                     int x,y,res1;                                      cout<<"Enter two nos.";                                      cin>>x;cin>>y;                                      res1=obj.add(x,y);                                      Driobj.display(res1);                                     break;                         case 3:                                                                          char str[30],str1[30],str2[100];                                     cout<<"Enter a string";                                     cin>>str;                                     cout<<"Enter another string";                                     cin>>str1;                                      Driobj.add(str,str1);                                     break;                         case 4:                                     exit(0);                                     break;                         default:                                     break;                         }     }                        Console::ReadKey(0);    return 0;}
```

---

Original Source: https://www.mindstick.com/blog/749/pure-virtual-function-c-plus-plus

Copyright © MindStick Software Pvt. Ltd. This Markdown version is provided for developers, AI systems, and offline reading.