Which of the following is a correct file extension for a C++ source file?
- .cpp
- .html
- .java
- .py
C++ source files typically have the extension ".cpp", although other extensions like ".cc" or ".cxx" are also used sometimes.
In a function that needs to return multiple values, which method of parameter passing might be employed to facilitate this without using data structures like tuples or pairs?
- Using global variables
- Using static variables
- Passing by reference
- Using std::vector
When parameters are passed by reference to a function, the function can modify the original values of those parameters. By passing additional parameters by reference, a function can effectively "return" more than one value without relying on composite data structures like tuples or pairs. This method is often used for out parameters in functions.
What does the break statement do in a loop structure?
- Exits the entire program.
- Skips to the next iteration.
- Exits the loop immediately.
- Continues to execute the loop from the start.
The break statement in C++ is used to exit the loop immediately, bypassing the rest of the loop's code and any remaining iterations. This can be especially useful for exiting a loop when a specific condition is met.
What could be a reason for choosing pass by pointer over pass by reference in a function?
- Allow null arguments
- To increase execution speed
- To reduce code complexity
- For automatic memory management
Pass by pointer allows for the possibility of passing a null argument. In contrast, references in C++ must always alias some object, meaning you can't have a null reference. When a function needs to accept a "no-object" situation, using a pointer can be preferable since it can be checked for nullity.
A _______ is a smart pointer that owns and manages another object through a pointer and disposes of that object when the _______ goes out of scope.
- auto_ptr
- unique_ptr
- shared_ptr
- raw_ptr
A unique_ptr in C++ is a type of smart pointer that owns a dynamically allocated object exclusively. It ensures that the owned object is properly deallocated once the unique_ptr that owns it goes out of scope, preventing memory leaks.
Imagine you are implementing a high-frequency trading system...
- std::fstream with buffering
- mmap based I/O
- std::cout
- std::ofstream with std::ios::sync_with_stdio(false)
mmap based I/O, which maps a file into memory, allows for very fast file operations since it avoids certain system calls and can result in fewer memory-copy operations than traditional read/write functions. This is crucial for high-frequency systems where latency is critical.
The _______ statement is used to prematurely exit a switch-case block.
- return
- break
- continue
- exit
The "break" statement is used to exit a switch-case block prematurely. Once a "break" is encountered, the control jumps out of the switch-case structure.
The _______ function is automatically called when an object is destroyed.
- destructor
- finalizer
- deleter
- remover
In C++, when an object's lifetime ends, its destructor is called automatically. A destructor is a member function with the same name as its class preceded by a tilde (~).
In the context of recursion, what is a "recursive case"?
- A case that ends the recursion
- A scenario where recursion isn't used
- A case that repeats the same steps
- A case that calls the function itself recursively
In recursive algorithms, the "recursive case" refers to the scenario or condition where the function calls itself. This is contrasted with the "base case", which provides a termination criterion for the recursion. Without a base case, recursive functions can run indefinitely, leading to a stack overflow. The recursive case helps break down the problem into smaller, more manageable sub-problems.
Which access specifier in C++ allows a class member to be accessible only within the class and friends of the class?
- public
- private
- protected
- external
The private access specifier in C++ ensures that class members are only accessible within the class and not outside. Additionally, friend functions or classes can access these private members, but they remain hidden from other parts of the program.