---
description: "Learn more about: override Specifier"
title: "override Specifier"
ms.date: "11/04/2016"
helpviewer_keywords: ["override Identifier"]
ms.assetid: b286fb46-9374-4ad8-b2e7-4607119b6133
---
# override Specifier

You can use the **override** keyword to designate member functions that override a virtual function in a base class.

## Syntax

```
function-declaration override;
```

## Remarks

**override** is context-sensitive and has special meaning only when it's used after a member function declaration; otherwise, it's not a reserved keyword.

## Example

Use **override** to help prevent inadvertent inheritance behavior in your code. The following example shows where, without using **override**, the member function behavior of the derived class may not have been intended. The compiler doesn't emit any errors for this code.

```cpp
class BaseClass
{
    virtual void funcA();
    virtual void funcB() const;
    virtual void funcC(int = 0);
    void funcD();
};

class DerivedClass: public BaseClass
{
    virtual void funcA(); // ok, works as intended

    virtual void funcB(); // DerivedClass::funcB() is non-const, so it does not
                          // override BaseClass::funcB() const and it is a new member function

    virtual void funcC(double = 0.0); // DerivedClass::funcC(double) has a different
                                      // parameter type than BaseClass::funcC(int), so
                                      // DerivedClass::funcC(double) is a new member function
};
```

When you use **override**, the compiler generates errors instead of silently creating new member functions.

```cpp
class BaseClass
{
    virtual void funcA();
    virtual void funcB() const;
    virtual void funcC(int = 0);
    void funcD();
};

class DerivedClass: public BaseClass
{
    virtual void funcA() override; // ok

    virtual void funcB() override; // compiler error: DerivedClass::funcB() does not
                                   // override BaseClass::funcB() const

    virtual void funcC( double = 0.0 ) override; // compiler error:
                                                 // DerivedClass::funcC(double) does not
                                                 // override BaseClass::funcC(int)

    void funcD() override; // compiler error: DerivedClass::funcD() does not
                           // override the non-virtual BaseClass::funcD()
};
```

To specify that functions cannot be overridden and that classes cannot be inherited, use the [final](../cpp/final-specifier.md) keyword.

## See also

[final Specifier](../cpp/final-specifier.md)<br/>
[Keywords](../cpp/keywords-cpp.md)