Why encapsulation is required in C++ - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a private member variable in a class.

C++

class Box {
private:
    int [1];
};

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

Aclass

Bpublic

Clength

Dvoid

Attempts:

3 left

💡 Hint

Common Mistakes

Using access specifiers like 'public' as variable names.

The private member variable length is declared inside the class to hide it from outside access.

2fill in blank

medium

Complete the code to provide a public method to access the private variable.

C++

class Box {
private:
    int length;
public:
    int [1]() {
        return length;
    }
};

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

AgetLength

BsetLength

Clength

DBox

Attempts:

3 left

💡 Hint

Common Mistakes

Using the variable name itself as the method name without 'get' prefix.

The method getLength is a public getter that allows controlled access to the private variable length.

3fill in blank

hard

Fix the error in the code to prevent direct access to the private variable.

C++

int main() {
    Box box;
    // box.length = 10; // Error: cannot access private member
    box.[1](10);
    return 0;
}

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

ABox

Blength

CgetLength

DsetLength

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to access the private variable directly.

Using the public setter method setLength allows setting the private variable length safely.

4fill in blank

hard

Fill both blanks to complete the setter method for the private variable.

C++

class Box {
private:
    int length;
public:
    void [1](int [2]) {
        length = [2];
    }
};

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

AsetLength

Bvalue

Clength

DgetLength

Attempts:

3 left

💡 Hint

Common Mistakes

Using the private variable name as the parameter name without distinction.

The setter method setLength takes a parameter value to assign to the private variable length.

5fill in blank

hard

Fill all three blanks to create a class demonstrating encapsulation with private variable and public getter and setter.

C++

class Box {
private:
    int [1];
public:
    void [2](int [3]) {
        length = [3];
    }
    int getLength() {
        return length;
    }
};

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

Alength

BsetLength

Cvalue

DgetLength

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up method names or parameter names.

This class uses encapsulation by keeping length private and providing public methods setLength and getLength to access it safely.