What is the lifetime of a static variable in a C program?
- Limited to the function it's defined in
- Same as the program's runtime
- Until the function exits
- Until the program exits
The lifetime of a static variable in C is the same as the program's runtime. It retains its value between function calls and persists until the program terminates.
Double pointers are often used in C to create a(n) ________ of pointers.
- Array
- Array of Pointers
- List
- Structure
Double pointers in C are often used to create an array of pointers, allowing you to work with multiple pointers efficiently.
You're tasked with optimizing a program that reads large text files. What strategies could you employ to improve the performance of the file reading operation?
- Employ memory-mapped files to reduce I/O operations.
- Ignore error handling to reduce overhead.
- Read the entire file into memory at once.
- Use a simple sequential read operation without any optimizations.
Utilizing memory-mapped files can reduce I/O operations and improve the performance of reading large text files. Loading the entire file into memory can lead to resource issues.
The members of a structure are accessed using the ________ operator.
- -> (arrow)
- . (dot)
- :: (scope)
- [] (brackets)
In C, members of a structure are accessed using the dot (.) operator.
You are working on an application that processes large datasets. How can using pointers and arrays together optimize the application?
- Enhance data security
- Improve data access speed
- Reduce memory usage
- Simplify user interface
Using pointers in conjunction with arrays can optimize an application by improving data access speed. Pointers can efficiently traverse and manipulate arrays, leading to faster data retrieval and processing, which is crucial when working with large datasets. This optimization benefits the application's performance.
In C, pointers can be used to pass ________ to a function.
- addresses
- constants
- data
- variables
In C, pointers can be used to pass addresses to a function. This allows functions to modify the original data.
Which preprocessor directive is used to include a header file in a C program?
- #define
- #ifdef
- #ifndef
- #include
The preprocessor directive #include is used to include a header file in a C program. It allows you to use functions and declarations from the included file in your program.
In a database application, you need to sort a list of names (strings) in alphabetical order. Which string handling function might be useful in this scenario?
- strchr
- strcmp
- strnlen
- strtok
To sort a list of names in alphabetical order, the strcmp function is useful. It compares two strings and returns a value indicating their relative order. strtok is used for tokenizing strings, strchr searches for a character in a string, and strnlen provides the length of a string up to a specified limit.
In a program managing a database of students, each student has attributes like name, age, and grades. How would pointers to structures be beneficial in this scenario?
- Enhance database security
- Improve data organization
- Minimize CPU usage
- Streamline user input
Pointers to structures can be beneficial in this scenario by improving data organization. By using pointers to structures, you can efficiently manage and access student information, such as name, age, and grades, making the database more organized and accessible. This optimization helps in effective data management.
What is a potential risk of using the gets() function for reading strings in C?
- It always returns NULL
- It can lead to buffer overflow
- It doesn't exist in C
- It has a higher time complexity
The gets() function is risky because it does not perform bounds checking and can lead to buffer overflows, potentially exposing the program to security vulnerabilities.