In what scenario might a program have a memory leak due to an exception being thrown?
- When the destructor isn't called
- When using global variables
- When an exception is caught and rethrown
- When exception specifications are used
A common memory leak scenario is when an exception is thrown before the memory allocated dynamically (usually with new) is deallocated. If the exception prevents a destructor or a delete statement from being reached, the memory is never released, resulting in a memory leak.
What is the primary purpose of using enum in C++?
- For iterating over collections
- For handling exceptions
- To create user-defined data types
- For memory management
The primary purpose of enum (short for "enumeration") in C++ is to create user-defined data types where you can define a set of named integer constants. It provides a way to assign names to integral constants, which makes a program easier to read and maintain.
You are developing a software library in C++ that will be used by other developers, and you want to ensure that the internal variables of your classes are not accessible while the methods are. How might encapsulation be implemented to achieve this while providing a clear API?
- Make all variables public and methods private.
- Make all methods and variables private.
- Make variables private and methods public.
- Only use static variables and methods.
Encapsulation is achieved by bundling data (variables) and methods that operate on the data into a single unit (class) and restricting the direct access to some of the object's components. In C++, this is implemented by declaring variables as private and providing public methods (API) to access and manipulate them.
What will be the result of the bitwise OR operation between 1101 and 1010 binary numbers?
- 1111
- 1100
- 111
- 1011
The bitwise OR operation works by comparing each bit position of the two numbers. If at least one bit is set (1) in a given position in either of the numbers, the resulting bit will be set. For 1101 OR 1010, the result is 1111.
What is the primary advantage of passing parameters by reference over passing them by value?
- Reduced memory usage
- Faster program execution
- Modifying the actual variable
- Ensuring data privacy
Passing parameters by reference allows for direct access to the original memory location, eliminating the need for copying data. This reduces memory overhead and can enhance the performance of the program. While options 2 and 3 can also be benefits of passing by reference, the primary advantage is the reduction of memory usage.
In a real-time gaming application written in C++, which smart pointer would you choose to manage instances of game objects, assuming the objects need to be shared across multiple game scenes?
- auto_ptr
- weak_ptr
- shared_ptr
- unique_ptr
shared_ptr allows multiple pointers to share ownership of the same object. This ensures that the object remains alive as long as there's at least one shared_ptr pointing to it, which is ideal for shared resources in games.
In C++ STL, which algorithm is most suitable for rearranging elements in a range, so they are in reversed order?
- sort()
- reverse()
- swap()
- rotate()
The reverse() algorithm in C++ STL is explicitly designed to reverse the elements in a specified range. While other algorithms like sort(), swap(), and rotate() have different primary purposes, only reverse() guarantees the desired effect for this use-case.
You are developing a simulation that runs in discrete time steps...
- Parallelize the simulation across multiple CPU cores.
- Decrease the resolution of the simulation.
- Use lazy evaluation for less critical calculations.
- Increase the time step size.
Parallelizing the simulation allows it to leverage the power of multi-core processors, thereby executing multiple parts of the simulation concurrently. This can lead to a substantial decrease in total simulation time, especially when there are many independent parts in the simulation.
What does the "++" symbolize in the C++ programming language?
- Double precision
- Enhancement to C
- Increment
- Two plus operations
The "++" in C++ symbolizes an "enhancement to C." Bjarne Stroustrup, when developing the language, considered C++ as an extension or improvement of the C language, hence the name C with an increment "++".
Who is the creator of the C++ programming language?
- Bjarne Stroustrup
- Dennis Ritchie
- Guido van Rossum
- James Gosling
Bjarne Stroustrup is the creator of C++. He developed it as an extension of the C programming language.