What is the purpose of the throw keyword in exception handling in C++?
- to propagate
- to hide
- to prevent
- to execute
In C++ exception handling, the throw keyword is used to signal the occurrence of an exception. When an error condition arises, using the throw keyword can help propagate the exception up the call stack until it's caught by an appropriate catch block.
How does the continue statement affect the execution of a nested loop structure?
- It jumps to the next iteration of the innermost loop.
- It jumps to the next iteration of the outermost loop.
- It stops the entire program execution.
- It restarts all loops from the beginning.
The continue statement causes the current iteration of the loop to terminate, and the control jumps to the next iteration of the innermost loop that contains the continue. It won't affect any outer loops in the nested structure unless it's placed in the outer loop itself.
What will happen if the break statement is used outside any loop or switch statement?
- The program will crash.
- It will skip the next statement.
- It results in a compilation error.
- It breaks out of the main function.
Using the break statement outside of a loop or switch will result in a compilation error. The break statement is meant to terminate the nearest enclosing loop or switch where it appears. If it's placed elsewhere, it won't make logical sense to the compiler.
The _______ keyword is used to specify a class should not be instantiated directly, but only used as a base class.
- virtual
- abstract
- sealed
- interface
In C++, an "abstract" class is one that cannot be instantiated directly. It is intended to be used as a base class from which other classes are derived, and it may have one or more pure virtual functions.
A function in your codebase is exhibiting unexpected behavior because it is being passed an argument of an incorrect type, but the compiler is not generating an error. What might be a potential reason for this, and how could it be resolved?
- The compiler is outdated.
- Function overloading is causing ambiguity.
- Argument type has an implicit conversion to the expected type.
- There's an error in the compiler settings.
Implicit type conversions in C++ can sometimes lead to unexpected behavior, especially if a function argument undergoes an unintended conversion. This can be resolved by either making the type conversion explicit or by using strong type checks and avoiding implicit conversions.
The keyword _______ is used to specify that a function should be compiled inline.
- auto
- static
- inline
- register
The "inline" keyword suggests to the compiler that it should attempt to embed the function's code in the place where the function is called, avoiding a function call.
How does the compiler handle inline function calls?
- By replacing the function call with its body.
- By linking the function at runtime.
- By creating a virtual table for the function.
- By allocating dynamic memory for the function.
Inline functions are meant to optimize function calls by eliminating the overhead of a call and return sequence. When the compiler inlines a function, it replaces the function call with the actual body of the function, integrating it directly into the calling code, which can improve performance.
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.