When a class contains a pointer to memory allocated in class, we should define a _______.
- destructor
- constructor
- overloader
- allocator
When a class contains a pointer that has memory allocated to it dynamically, it's crucial to have a destructor to release that memory when the object is destroyed to prevent memory leaks.
The conditions in a switch-case statement must be of _______ data type.
- floating
- string
- integer or enum
- boolean
In a switch-case structure in C++, the conditions or cases must be of an integer or enumeration type. Floating-point and boolean values cannot be used as cases.
In a for loop, what will happen if the condition is omitted?
- It will throw a syntax error.
- The loop will execute once.
- The loop will never execute.
- The loop will execute indefinitely.
In a for loop, if the condition is omitted, it's treated as always true. Therefore, the loop will execute indefinitely unless there's a break statement or some external factor that interrupts its execution.
What is the primary difference between direct and indirect recursion?
- Direct calls itself, while indirect calls another function that calls it back.
- Direct uses less memory than indirect.
- Direct is slower than indirect.
- Direct is always safer than indirect.
Direct recursion occurs when a function calls itself directly, whereas indirect recursion involves a function calling another function that eventually calls the original function. It's a cycle of calling between two or more functions.
When dealing with binary files, the ios::binary mode should be used in conjunction with another mode such as _______.
- ios::in
- ios::out
- ios::app
- ios::trunc
When working with binary files in C++, the ios::binary mode is often paired with another mode to specify the operation, such as ios::out for writing or ios::in for reading. This ensures that the file is treated as a binary file.
How would you implement a loop that executes a specific number of times and uses an iterator?
- Use a while loop and initialize the iterator outside the loop.
- Use a range-based for loop.
- Use a for loop and compare the iterator to the container's end iterator.
- Use recursive function calls.
To execute a loop for a specific number of times using an iterator, a common approach is to use a for loop. You initialize the iterator before the loop starts, use the loop's condition to check against the container's end iterator, and increment the iterator within the loop's iteration expression.
What is a destructor used for in C++?
- To allocate memory.
- To initialize objects.
- To handle exceptions.
- To release resources.
A destructor is a special member function of a class that is executed whenever an object of that class goes out of scope or is explicitly destroyed. Its primary role is to release any resources that the object may have acquired during its lifetime.
The function _______ is used to close a file.
- fstream
- read
- close
- write
The close function is used in conjunction with file streams in C++ to close an open file. It's crucial to close files after operations to release system resources and ensure that all changes, if any, are flushed and saved appropriately to the file system.
What is the use of a catch block with an ellipsis (...)?
- To catch integer exceptions.
- To catch all exceptions irrespective of its type.
- To denote omission in code.
- To handle multiple exceptions at once.
A catch block with an ellipsis (...) is used to catch all exceptions, irrespective of their type. This can be useful when you want to ensure that no exceptions go unhandled, but it's often a good practice to handle specific exceptions with their respective catch blocks.
What is the primary purpose of the break statement in C++ loops?
- To skip the next iteration
- To pause the loop for a moment
- To terminate the loop
- To reduce execution time
The break statement in C++ is used to terminate the loop, irrespective of whether the loop's condition has been met or not. This can be useful when a certain condition, separate from the loop's terminating condition, is met and the loop needs to end prematurely.
In a financial application, you are processing transaction data in a loop. When a fraudulent transaction is detected, it needs to be logged and then the processing needs to continue with the next transaction. How would the continue statement be utilized effectively in this scenario?
- To exit the application.
- To restart the loop from the beginning.
- To skip the fraudulent transaction and continue with the next.
- To reprocess the fraudulent transaction.
The continue statement is used to skip the current iteration of a loop and move to the next one. In the given scenario, once a fraudulent transaction is detected and logged, the continue statement can be used to skip any further processing for that transaction and immediately start processing the next transaction in the loop.
In a large-scale C++ project, two classes, Logger and FileHandler, are tightly coupled, sharing a lot of private data between them using friendship. How might you refactor these classes to reduce coupling without losing functionality?
- Combine both classes into a single class.
- Extract shared functionality into a separate utility class.
- Create global variables for shared data.
- Introduce an intermediary interface.
Introducing an intermediary interface or abstraction can decouple these classes. This interface can define the necessary methods and data that both classes need, allowing them to interact without direct access to each other's private data, leading to better separation of concerns.