In C++, an abstract class can have a mix of abstract as well as _______ methods.
- concrete
- private
- static
- virtual
An abstract class in C++ can have both abstract methods (methods without any definition) and concrete methods (methods with a definition). This allows for a mix of defined and undefined behaviors in subclasses.
Which type of class inheritance allows a derived class to inherit attributes and methods from more than one base class?
- Single
- Multilevel
- Multiple
- Hierarchical
Multiple inheritance in C++ allows a derived class to inherit attributes and methods from more than one base class. This contrasts with single inheritance where a class can inherit only from one superclass. C++ supports multiple inheritance, unlike some other OO languages.
The function _______ allows you to swap the elements of two containers in C++ STL.
- push_back
- begin
- swap
- emplace_back
The swap function in C++ STL allows for a quick swap of elements between two containers. This operation is usually done in constant time as only the internal pointers are exchanged.
In C++ STL, the function _______ is used to remove consecutive duplicate elements in a range.
- remove
- unique
- delete
- erase
The unique algorithm in C++ STL is used to eliminate consecutive duplicate elements from a range. The range after the unique elements is left with unspecified values.
The keyword _______ is used to grant a function or class access to the private and protected members of another class in C++.
- using
- friend
- grant
- access
The keyword "friend" in C++ is used to specify that a particular external function or another class can access the private and protected members of the class in which it is declared. This is fundamental to the concept of friend functions and friend classes.
You are working on a large-scale simulation software where numerous animal species are modeled. Which type of inheritance might be most suitable to model individual animal species without encountering the diamond problem?
- Single Inheritance
- Multiple Inheritance
- Hierarchical Inheritance
- Multilevel Inheritance
Single inheritance ensures that a class inherits from only one other class, thus avoiding the diamond problem. The diamond problem arises in languages that support multiple inheritance and can result in ambiguity in the inheritance hierarchy. Single inheritance ensures a clear, linear progression without any ambiguities.
What is the primary reason for using smart pointers over raw pointers in modern C++?
- To increase execution speed
- To use less memory
- To look modern
- To manage memory automatically
Smart pointers, such as unique_ptr, shared_ptr, and weak_ptr, were introduced in C++ to provide automated memory management. They automatically handle the destruction of objects they point to, thereby preventing common issues like memory leaks and dangling pointers.
What is the role of the return statement in a lambda function?
- To indicate the end of the lambda function.
- To return a value from the lambda to the calling function.
- It determines the type of the lambda.
- It can't be used in lambda functions.
Lambda functions, like regular functions, can return values. If the lambda's body contains more than one statement, a return statement can be used to specify which value is returned. If the lambda's body consists of a single return statement, the return type is automatically inferred by the compiler.
Imagine you're refactoring a legacy C++ codebase. It heavily uses friend functions, leading to a maintenance burden and difficult-to-follow code. What strategy might you adopt to improve encapsulation and maintainability without sacrificing performance?
- Use inheritance exclusively.
- Encapsulate the required data and use getter/setter functions.
- Make all data public to avoid using friend functions.
- Refactor to use forward declarations.
While getter and setter methods might introduce a slight overhead, modern compilers can inline these functions to ensure minimal performance impact. By encapsulating data, you enhance the maintainability and structure of the code.
Imagine a scenario where you have to maintain a collection of elements while keeping them sorted after insertions and deletions. Which STL container would be the most efficient choice for this task?
- vector
- list
- set
- queue
The STL set container maintains its elements in sorted order by keys. It automatically reorders itself after insertions and deletions, making it the most efficient choice for maintaining a sorted collection without requiring manual reordering.