Override Identifier in C++

Override Identifier in C++ – Explained with Examples

Imagine you have a parent and a child. The parent has a rule, like “Always be polite.” The child wants to follow the same rule but in their own way. In C++, when a child class follows (or overrides) a rule from the parent class, we use the word override to make that clear.

In programming, a class is like a blueprint. One class can be based on another this is called inheritance. If the child class wants to change a function from the parent class, we say it is overriding it.

The override keyword helps the computer understand that this function is meant to replace the one in the parent class.

Why do we need override?

It helps avoid mistakes. Without override, if you type something wrong like giving the function the wrong name or wrong inputs — the computer will think it’s a new function, not a replacement. This can cause bugs in your program. With override, if something is wrong, the computer will give you an error immediately. This saves time and prevents confusion.

Example Without override (Wrong Behavior)

class Animal {
public:
    virtual void makeSound() {
        cout << "Some generic sound" << endl;
    }
};

class Dog : public Animal {
public:
    void makeSond() {  // Spelling mistake
        cout << "Bark!" << endl;
    }
};

Here, Dog is trying to override the makeSound() function from Animal, but due to the spelling mistake (makeSond), it doesn’t work. The computer won’t give an error, and your code will run but not as expected.

Example With Override (Correct and Safe)

class Animal {
public:
    virtual void makeSound() {
        cout << "Some generic sound" << endl;
    }
};

class Dog : public Animal {
public:
    void makeSound() override {
        cout << "Bark!" << endl;
    }
};

Here, everything is correct, and Dog will correctly replace the function from Animal. If you make a mistake, the compiler will stop you and show an error.

Key Points to Remember

override is used when a child class wants to change the behavior of a function from its parent class.
It only works with virtual functions (functions that can be overridden).
It helps catch errors early.

Conclusion

The override keyword is like a safety check in C++. It tells the computer, “This function is meant to replace one from the parent class.” If something is wrong, it will show an error and help you fix it.

Tip: If you’re ever writing code that inherits from another class, always use override when changing a function. It’s good practice, even for beginners.