Try–catch block in C++ - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to catch an exception thrown inside the try block.

C++

try {
    throw std::runtime_error("Error occurred");
} catch ([1]) {
    std::cout << "Exception caught" << std::endl;
}

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

Aconst std::exception& e

Bint e

Cdouble e

Dchar e

Attempts:

3 left

💡 Hint

Common Mistakes

Catching exceptions by value instead of by reference.

Using incorrect exception types like int or char.

The catch block should catch exceptions by reference to std::exception or its derived classes to handle standard exceptions properly.

2fill in blank

medium

Complete the code to throw a standard exception with a message.

C++

void test() {
    [1] std::runtime_error("Something went wrong");
}

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Athrow

Bcatch

Ctry

Dreturn

Attempts:

3 left

💡 Hint

Common Mistakes

Using try or catch instead of throw.

Forgetting to throw the exception object.

The throw keyword is used to raise an exception in C++.

3fill in blank

hard

Fix the error in the catch block to properly catch all exceptions.

C++

try {
    // some code
} catch ([1]) {
    std::cout << "Caught an exception" << std::endl;
}

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Aint e

Bstd::exception e

Cchar e

D...

Attempts:

3 left

💡 Hint

Common Mistakes

Catching exceptions by value instead of reference.

Not catching all exception types.

Using ... in catch block catches all exceptions regardless of type.

4fill in blank

hard

Fill both blanks to catch a standard exception and print its message.

C++

try {
    throw std::runtime_error("Error");
} catch ([1]) {
    std::cout << e.[2]() << std::endl;
}

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Aconst std::exception& e

Bwhat

Cmessage

Dconst char* e

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect exception types.

Trying to access a non-existent method like message().

Catch the exception by reference and use the what() method to get the error message.

5fill in blank

hard

Fill all three blanks to throw and catch a custom exception with a message.

C++

class MyException : public std::exception {
public:
    const char* [1]() const noexcept override {
        return "Custom error";
    }
};

int main() {
    try {
        [2] MyException();
    } catch ([3]) {
        std::cout << e.what() << std::endl;
    }
    return 0;
}

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

Awhat

Bthrow

Cconst MyException& e

Dcatch

Attempts:

3 left

💡 Hint

Common Mistakes

Not overriding what() correctly.

Catching exceptions by value instead of reference.

Using catch keyword incorrectly.

The method what() returns the error message. Use throw to raise the exception and catch it by reference.