Access control in inheritance in C++ - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a class B that inherits publicly from class A.

C++

class B : [1] A {};

Drag options to blanks, or click blank then click option'

Aprotected

Bprivate

Cpublic

Dvirtual

Attempts:

3 left

💡 Hint

Common Mistakes

Using private or protected inheritance changes access levels unexpectedly.

Using public inheritance means all public members of A remain public in B.

2fill in blank

medium

Complete the code to make class B inherit privately from class A.

C++

class B : [1] A {};

Drag options to blanks, or click blank then click option'

Aprivate

Bpublic

Cprotected

Dvirtual

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing private inheritance with private members.

Private inheritance means all public and protected members of A become private in B.

3fill in blank

hard

Fix the error in the code to allow class B to access protected members of class A.

C++

class A {
protected:
    int x;
};

class B : [1] A {
public:
    void setX(int val) { A::x = val; }
};

Drag options to blanks, or click blank then click option'

Apublic

Bprivate

Cprotected

Dvirtual

Attempts:

3 left

💡 Hint

Common Mistakes

Using private inheritance blocks access to protected members.

Public inheritance allows B to access protected members of A.

4fill in blank

hard

Fill both blanks to declare class B that inherits protectedly from class A and class C that inherits publicly from B.

C++

class B : [1] A {};
class C : [2] B {};

Drag options to blanks, or click blank then click option'

Aprotected

Bprivate

Cpublic

Dvirtual

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up protected and public inheritance keywords.

Class B inherits protectedly from A, so A's public and protected members become protected in B.
Class C inherits publicly from B, so B's protected members remain protected in C.

5fill in blank

hard

Fill all three blanks to create a class D that inherits publicly from B and privately from C, where B inherits publicly from A and C inherits protectedly from A.

C++

class B : [1] A {};
class C : [2] A {};
class D : [3] B, private C {};

Drag options to blanks, or click blank then click option'

Apublic

Bprotected

Cprivate

Dvirtual

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing inheritance access specifiers and their effects on member visibility.

B inherits publicly from A, so A's public members stay public in B.
C inherits protectedly from A, so A's public and protected members become protected in C.
D inherits publicly from B, so B's public members stay public in D, and privately from C, so C's members become private in D.