Destructor role in C++ - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a destructor in a C++ class.

C++

class MyClass {
public:
    ~[1]();
};

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Adelete

BmyClass

CDestructor

DMyClass

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different name than the class for the destructor.

Omitting the tilde (~) before the destructor name.

The destructor has the same name as the class, preceded by a tilde (~).

2fill in blank

medium

Complete the code to define a destructor that prints a message when called.

C++

MyClass::~MyClass() {
    std::cout << [1] << std::endl;
}

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ADestructor_called

BDestructor called

C"Destructor called"

Ddestructor

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting the quotes around the message string.

Using a variable name instead of a string literal.

The message must be a string literal enclosed in double quotes.

3fill in blank

hard

Fix the error in the destructor declaration.

C++

class MyClass {
public:
    ~MyClass[1];
};

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A{}

B()

C;

D[]

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting parentheses in the destructor declaration.

Using braces {} instead of parentheses ().

The destructor declaration must include empty parentheses ().

4fill in blank

hard

Fill both blanks to complete the destructor definition that frees a dynamically allocated array.

C++

class MyClass {
    int* data;
public:
    MyClass() { data = new int[10]; }
    ~MyClass() {
        [1] data;
        data = [2];
    }
};

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Adelete[]

Bnullptr

C0

Ddelete

Attempts:

3 left

💡 Hint

Common Mistakes

Using delete instead of delete[] for arrays.

Not setting pointer to nullptr after deletion.

Use delete[] to free arrays and set pointer to nullptr to avoid dangling pointers.

5fill in blank

hard

Fill all three blanks to complete the destructor that closes a file and resets the pointer.

C++

class FileHandler {
    FILE* file;
public:
    FileHandler(const char* filename) {
        file = fopen(filename, "r");
    }
    ~FileHandler() {
        if ([1] != nullptr) {
            [2](file);
            file = [3];
        }
    }
};

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Afile

Bfclose

Cnullptr

Dopen

Attempts:

3 left

💡 Hint

Common Mistakes

Not checking if file pointer is nullptr before closing.

Using wrong function to close the file.

Not resetting pointer after closing.

Check if file is not nullptr, then close it with fclose, and reset pointer to nullptr.