When using typedef to create a function pointer alias, what aspect of the function signature must be included in the alias?
- Function name
- Return type
- Parameter types
- Number of parameters
The correct option is b) Return type. When using typedef to create a function pointer alias, you must include the return type of the function in the alias. This ensures that the alias correctly represents the function pointer's signature, allowing you to use it to declare and call functions.
When reading a file in C, which function can be used to check if the end of the file has been reached?
- endOfFile()
- feof()
- fileEOF()
- file_end()
The correct function is feof(), which stands for "file end of file." It returns a non-zero value if the end of the file has been reached, indicating that there are no more characters to read.
In which scenarios would it be beneficial to use double pointers in C?
- Dynamic memory allocation
- Linked lists
- Matrix operations
- String manipulations
Double pointers are often used in scenarios like linked lists, where you need to manage a list of pointers. They also come in handy when dealing with matrices and strings, as they allow you to have multiple levels of indirection for better control and memory management.
What function is commonly used to find the length of a string in C?
- strcat()
- strcmp()
- strcpy()
- strlen()
In C, strlen() is commonly used to find the length of a string. It counts the number of characters in a string until the null-terminator is encountered.
A ________ occurs when a program continues to use a pointer after it has been freed.
- Buffer Overflow
- Dangling Pointer
- Memory Leak
- Segmentation Fault
A Dangling Pointer occurs when a program continues to use a pointer after it has been freed. This can lead to undefined behavior, crashes, or data corruption. It's crucial to avoid using pointers that point to memory that has been deallocated.
Why would you use a pointer to an array instead of a regular array in a function?
- Pointers allow you to modify the original array in a function.
- Pointers allow you to pass arrays to functions without making a copy.
- Pointers are more memory-efficient than regular arrays.
- Pointers provide a way to dynamically allocate memory for arrays.
Using a pointer to an array in a function allows you to pass the array by reference, avoiding the need to make a copy of the array. This is more memory-efficient and allows you to modify the original array within the function.
When working with binary files, the ________ function can be used to read data in a structured manner.
- fread()
- fgets()
- fgetc()
- fscanf()
The correct option is fread(). This function is specifically designed for reading binary data from a file. It takes parameters like the file pointer, size of each element, number of elements, and the destination buffer where the data will be stored. This makes it suitable for structured reading of binary files.
What does the fseek function do in a C program?
- Sets the file position indicator to the beginning
- Moves the file position indicator to the end
- Positions the file pointer to a specified location
- Closes the file
The correct option is c. Positions the file pointer to a specified location. The fseek() function in C is used to set the file position indicator to a specific location within the file, allowing random access and manipulation of file contents.
You're developing a database system and need to frequently update records. What file handling technique would you use to efficiently update specific records without reading the entire file?
- Direct File Updating
- Indexed File Updating
- Random File Updating
- Sequential File Updating
Indexed File Updating would be the most efficient technique for frequently updating specific records in a database system. With an index, the system can quickly locate and update the desired record without the need to read the entire file sequentially. This reduces the time and resources required for updates, making it a suitable choice for scenarios where frequent record updates are a common operation in a database.
In the context of searching algorithms, why might a binary search be preferred over a linear search?
- Binary search guarantees to find the target quickly
- Binary search is always faster
- Binary search requires sorted data
- Binary search works for unsorted data
Binary search is preferred when data is sorted as it allows for efficient searching, while a linear search works for unsorted data.