C++ “virtual” keyword for functions in derived classes. Is it necessary?

Question

With the struct definition given below...

struct A {
    virtual void hello() = 0;
};

Approach #1:

struct B : public A {
           


        

Answer 1

Adding the "virtual" keyword is good practice as it improves readability , but it is not necessary. Functions declared virtual in the base class, and having the same signature in the derived classes are considered "virtual" by default.