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.
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.
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.
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.
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.
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.
The ________ sorting algorithm repeatedly steps through the list, compares adjacent elements and swaps them if they are in the wrong order.
- Binary
- Bubble
- Merge
- Quick
The 'Bubble' sorting algorithm repeatedly steps through the list, comparing adjacent elements, and swapping them if they are in the wrong order. It is a simple sorting algorithm but not very efficient for large datasets.
When writing data to a text file, which function is used to ensure that the data is written correctly?
- fprintf
- fputc
- fputs
- fwrite
The fprintf function is used to write formatted data to a text file in C. It allows you to specify the format and data to be written, ensuring that the data is written correctly with appropriate formatting.
The ______ stream in C is used for unbuffered error messages.
- stderr
- stdout
- printf
- ferror
The correct option is a) stderr. The stderr stream is used for unbuffered error messages in C programs.
The fseek function allows for ________ access of data within a file.
- random
- direct
- sequential
- indexed
The correct option is sequential. The fseek() function, when used with SEEK_SET, SEEK_CUR, or SEEK_END, allows for sequential access to data within a file. It enables you to move the file pointer forward or backward, or directly to the end of the file, facilitating sequential data access.
In a large C program, you notice that a variable is being used in multiple functions but is not behaving as expected. What could be the potential issue regarding the scope of the variable?
- The variable is a global variable
- The variable is a local variable
- The variable is a static variable
- The variable is an automatic variable
The potential issue with the variable not behaving as expected could be that it is a global variable. Global variables have a larger scope and can be modified by multiple functions, which may lead to unintended changes. It's important to be cautious when using global variables in large programs. Static variables retain their values but have a limited scope, making them less likely to cause scope-related issues. Automatic and local variables are confined to individual functions and are less likely to impact other parts of the program.
You're working on an embedded system with limited memory. What feature of C would you use to efficiently pack multiple flags into a single byte?
- Bit fields
- Pointers
- Inline functions
- Function pointers
Option A, "Bit fields," is the correct choice. Bit fields allow you to efficiently pack multiple boolean flags into a single byte, which is essential in resource-constrained embedded systems, helping to save memory. Bit fields provide control over the size and alignment of data within a structure, allowing you to use memory more efficiently. Other options are not typically used for this purpose and may not offer the same level of memory optimization. Bit fields are an important concept for embedded systems programming.