Data hiding in C++ - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

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

C++

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

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

Aclass

Bpublic

Cvoid

Ddata

Attempts:

3 left

💡 Hint

Common Mistakes

Using keywords like 'public' or 'void' as variable names.

Forgetting to declare the variable under 'private:'.

The private member variable is declared with a name like data. Keywords like public, void, or class are not valid variable names.

2fill in blank

medium

Complete the code to provide a public method that accesses the private variable.

C++

class MyClass {
private:
    int data;
public:
    int [1]() {
        return data;
    }
};

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AgetData

BsetData

Cdata

Dprivate

Attempts:

3 left

💡 Hint

Common Mistakes

Naming the method 'setData' when it should return the value.

Using the variable name 'data' as the method name.

The method to access a private variable is usually called a getter, commonly named getData. setData is for setting values, and data or private are not method names here.

3fill in blank

hard

Fix the error in the code to correctly set the private variable using a public method.

C++

class MyClass {
private:
    int data;
public:
    void setData(int value) {
        [1] = value;
    }
};

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

Adata

Bvalue

CsetData

Dthis->value

Attempts:

3 left

💡 Hint

Common Mistakes

Assigning the parameter to itself like 'value = value;'.

Using 'this->value' when the private variable is named 'data'.

The private variable data should be assigned the value passed to the method. Using data = value; correctly sets the private member.

4fill in blank

hard

Fill both blanks to create a class with a private variable and a public getter method.

C++

class Person {
private:
    [1] age;
public:
    [2] getAge() {
        return age;
    }
};

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Aint

Bvoid

Dfloat

Attempts:

3 left

💡 Hint

Common Mistakes

Using void as the return type for a getter method.

Declaring the variable as float when it should be int.

The private variable age should be of type int. The getter method returns an int value, so its return type is also int.

5fill in blank

hard

Fill all three blanks to define a class with a private string variable, a setter, and a getter.

C++

class Book {
private:
    [1] title;
public:
    void [2]([3] t) {
        title = t;
    }
    std::string getTitle() {
        return title;
    }
};

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

Astd::string

BsetTitle

Dint

Attempts:

3 left

💡 Hint

Common Mistakes

Using int instead of std::string for the variable or parameter.

Naming the setter method incorrectly.

The private variable title is of type std::string. The setter method is named setTitle and takes a parameter of type std::string.