What is the primary purpose of using pointers in a C function?
- To allocate memory dynamically
- To execute loops
- To perform arithmetic operations
- To store character data
Pointers in C allow you to allocate memory dynamically. They are often used to work with data structures, dynamic memory allocation, and creating flexible functions.
Which function is used to close a file that has been opened using fopen?
- fclose
- fopen
- fread
- fwrite
The fclose function is used to close a file that has been opened using fopen. This is important to release system resources and ensure data is properly saved.
When would it be beneficial to use a function pointer instead of a direct function call?
- Dynamically choosing a function to execute
- Enhancing compile-time error checking
- Reducing code complexity
- Simplifying code structure
Using a function pointer is beneficial when you need to dynamically choose a function to execute at runtime. It offers flexibility and is useful in various scenarios.
What is the time complexity of the bubble sort algorithm in the best case?
- O(1)
- O(log n)
- O(n)
- O(n^2)
The best-case time complexity of the bubble sort algorithm is O(n) when the array is already sorted, and no swaps are required during the pass.
When declaring a variable in C, what does the 'static' keyword do to the variable's lifetime?
- Doesn't affect it
- Extends it
- Initializes it
- Shortens it
The 'static' keyword in C extends the lifetime of a variable, allowing it to retain its value between function calls, making it suitable for data that persists.
You're developing an embedded system with limited memory and need to define several constants representing the states of a system. Which C construct would be most appropriate to use?
- Using functions
- Using global variables
- Using local variables
- Using macros
In an embedded system with limited memory, using macros would be most appropriate for defining constants as they are preprocessor directives and are more memory-efficient than global or local variables. Functions are not used for constants.
You are working on a software project in C++ that requires sorting a list of items in multiple ways. How could you leverage function overloading to achieve this?
- Define multiple functions with the same name but different parameters for each sorting method.
- Implement a single function with the most generic sorting algorithm to handle all sorting needs.
- Use inline functions for sorting, allowing for multiple sorting methods within one function.
- Utilize global variables to store sorting methods for easy access and reuse.
Function overloading in C++ allows you to define multiple functions with the same name but different parameters, enabling the use of various sorting methods for different data types.
How do you declare a pointer to an integer in C?
- int ptr;
- int* ptr;
- int_pointer ptr;
- pointer(int) p;
To declare a pointer to an integer in C, you use the format int* ptr;. This declares a pointer variable named ptr that can store the address of an integer.
You are developing a large-scale simulation that runs for a long duration. After running for a few hours, you notice the program slows down significantly. What could be a likely reason for this behavior?
- CPU Overheating
- Memory Leak
- Network Latency
- Software Bug
A memory leak is a common reason for slowing down a long-running program. It occurs when memory is allocated but not released, leading to resource exhaustion and slow performance.
You need to implement a function that modifies multiple variables of different data types. What concept related to pointers would you use?
- Arrays of pointers
- Function pointers
- Generic pointers
- Typecasting pointers
Typecasting pointers would allow you to change the data type of a pointer to manipulate variables of different data types in a single function.