Can you explain the meaning and usage of the keyword override in programming?

The keyword override is used in programming languages such as C++ (starting from C++11) to explicitly indicate that a method in a derived class overrides a virtual method in the base class.

This helps the compiler verify that the method indeed overrides an existing virtual method and warn about errors, for example, if the method signature does not match.

Example in C++:

class Base {
public:
    virtual void foo();
};

class Derived : public Base {
public:
    void foo() override; // Explicit override
};

If in Derived you write void foo(int) override;, the compiler will generate an error because there is no foo(int) method in the base class to override.