How does the performance of a switch-case statement compare to if-else if-else chains, especially when dealing with a large number of conditions?
- switch-case is always slower than if-else chains.
- switch-case and if-else chains have similar performance.
- if-else chains are always slower than switch-case.
- Performance is dependent on the compiler optimization.
While the performance of switch-case statements and if-else chains can depend on various factors, often, the switch-case statement is more optimized by compilers when dealing with a large number of conditions. The reason being, the compiler can optimize switch-case into a jump table or an array of branch instructions. However, it's always crucial to profile code in practice as the optimization might vary with compiler implementations and versions.
What is the potential risk of passing parameters by reference?
- Performance overhead
- Inability to return values
- Accidental data modification
- Pointers become null
Passing parameters by reference gives a function direct access to the original data. This can be risky as inadvertent changes in the function can lead to unintended modifications to the data. Care must be taken to ensure the integrity of the data and to avoid unexpected side effects. This risk doesn't exist when passing parameters by value since the function works with a copy of the data.
The use of _______ in nested if-else structures can sometimes enhance readability and maintainability of the code.
- curly braces
- semicolons
- return statements
- comments
Using curly braces { } in nested if-else structures ensures clear block demarcation, helping readers understand the scope and flow of the code. Without them, it's easy to misinterpret where conditions start and end, especially in deep nesting.
The _______ header file in C++ provides a set of functions to manipulate C strings and arrays.
The header file provides a set of functions for manipulating C-style strings and arrays. This includes functions like strcpy, strlen, and others.
What is the purpose of the modulus operator (%) in C++?
- Multiplication
- Addition
- Division
- Remainder Calculation
The modulus operator (%) in C++ is used to calculate the remainder of a division operation between two integers. It is especially useful when we need to determine if a number is divisible by another.
In C++20, using enum with _______ allows specifying the underlying type and scope.
- type specificity
- class
- explicit type
- annotations
In C++20, when using enum with "class", it allows the developer to specify both the underlying type and the scope. This gives better control and clarity over enumeration definitions.
What is the primary purpose of a constructor in a class?
- To delete instances of a class.
- To declare variables.
- To initialize object properties.
- To control memory allocation.
A constructor is a special member function of a class that is executed whenever a new object of that class is created. Its primary role is to initialize the attributes or properties of the class, ensuring that the object starts its life in a controlled state.
A C++ application is experiencing crashes due to memory corruption. During debugging, you notice that a function modifies the memory location of a pointer passed to it, affecting other parts of the application. Which concept might help prevent this issue in future implementations?
- Dynamic memory allocation
- Const correctness
- Inline functions
- Namespace utilization
"Const correctness" is a concept in C++ that ensures certain functions or methods don't modify the data they're working on. By declaring pointers or references as 'const', you're ensuring that they can't be used to modify the underlying data. This provides a level of safety against unintended side-effects and potential sources of memory corruption.
A tail-recursive function often can be rewritten iteratively using a _______.
- stack
- queue
- loop
- array
A tail-recursive function has its recursive call as the last action, which means the function doesn't need to hold onto its context or any other state between recursive calls. This nature allows it to be easily translated into an iterative structure, primarily using loops.
The new operator in C++ throws an exception of type _______ when it fails to allocate memory.
- invalid_type
- bad_memory
- bad_alloc
- new_failure
In C++, if the new operator fails to allocate the requested memory, it throws an exception of type bad_alloc. This is especially useful in situations where robustness is necessary, as it allows programs to handle memory allocation failures gracefully.