Base and derived classes in C++ - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a base class in C++?

A base class is a class that provides properties and behaviors (methods) which can be inherited by other classes called derived classes.

beginner

What is a derived class?

A derived class is a class that inherits properties and behaviors from a base class and can add its own features or modify existing ones.

beginner

How do you declare a derived class from a base class in C++?

Use the syntax: <br> <code>class DerivedClass : access_specifier BaseClass { ... };</code> <br> where <code>access_specifier</code> is usually <code>public</code>.

intermediate

What happens if a derived class does not define a constructor?

The derived class automatically calls the base class's default constructor to initialize the base part of the object.

intermediate

Can a derived class access private members of its base class directly?

No, private members of a base class are not accessible directly by derived classes. They can be accessed through public or protected methods of the base class.

Which keyword is used to inherit a class in C++?

A extends

B inherit

C class

D :

In C++, inheritance is declared using a colon ':' after the derived class name.

If class B inherits publicly from class A, which members of A are accessible in B?

A private members only

B all members

C public and protected members

D none

Public inheritance allows derived class to access public and protected members of the base class.

What is the default access specifier for inheritance in C++ classes?

A private

B none

C protected

D public

If no access specifier is given, inheritance is private by default in C++ classes.

Which of these is true about constructors in derived classes?

A Derived class constructors must call base class constructors explicitly.

B Base class default constructor is called automatically if not specified.

C Derived class constructors do not call base class constructors.

D Derived class cannot have constructors.

If a derived class constructor does not specify a base constructor, the base class's default constructor is called automatically.

Can a derived class override a base class method?

A Yes, if the base method is virtual.

B No, methods cannot be overridden.

C Only if the method is private.

D Only if the method is static.

In C++, a derived class can override a base class method if it is declared virtual in the base class.

Explain how inheritance works between a base class and a derived class in C++.

Think about how the derived class gets features from the base class.

Describe the role of constructors in base and derived classes during object creation.

Consider which constructor runs first and how the base part is initialized.