When passing by reference, changes made to the parameter within the function _______ the original argument.
- alter
- bypass
- skip
- hide
When passing arguments by reference in C++, any modifications made to the parameter within the function directly alter the original argument. This is different from passing by value, where the function works on a copy and the original remains unchanged.
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.
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.
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.
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 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.
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 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.
A function that calls itself directly or indirectly is known as a _______ function.
- recursive
- iterative
- overloaded
- main
A function that calls itself, either directly or by calling another function that eventually results in the original function being called again, is termed recursive.
In C++, which keyword is used to declare an abstract class?
- virtual
- volatile
- pure
- abstract
An abstract class in C++ is a class that cannot be instantiated and is meant to be inherited by other classes. It's declared using the virtual keyword, especially when a virtual function is set to 0, making it a pure virtual function, thus making the class abstract.