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, ______ is the standard error output stream.
- stdout
- stderror
- stderr
- errorout
The correct option is c) stderr. The standard error output stream is represented by stderr in C.
While reviewing a C program, you come across a scenario where a pointer is freed but later used in the program. What issue could this lead to?
- Buffer Overflow
- Memory Leak
- Null Pointer Exception
- Stack Overflow
Attempting to use a pointer after it has been freed can result in a null pointer exception, causing the program to crash or behave unpredictably.
You are developing a log monitoring tool that needs to constantly read a log file and process new entries. What approach would you take to efficiently read the file?
- Employ multi-threading to parallelize log file reading.
- Periodically restart the application to clear the file buffer.
- Use a polling mechanism to check for file changes.
- Use a single-threaded approach to read the file sequentially.
Efficient log file reading often involves multi-threading to process entries concurrently, leading to better performance.
You're working on a program that continuously monitors sensor data and reacts when a certain threshold is reached. Which loop construct would be most suitable for this task?
- do-while loop
- for loop
- if-else statement
- while loop
The most suitable loop construct for continuously monitoring sensor data is a 'while loop.' A while loop checks a condition and executes its code block repeatedly as long as the condition is true. This allows continuous monitoring until the threshold is reached.
What is the significance of the size_t return type in the fwrite function?
- It determines the file's size.
- It indicates the file's creation date.
- It is used to specify the file mode.
- It represents the number of items written to the file.
The size_t return type in the fwrite function signifies the number of items successfully written to the file. This is important for checking the success of the write operation.
What is the difference between malloc and calloc in terms of initialization of the allocated memory?
- Calloc initializes memory to an undetermined value.
- Calloc initializes memory to zero.
- Malloc initializes memory to an undetermined value.
- Malloc initializes memory to zero.
Malloc initializes memory to an undetermined value, while calloc initializes memory to zero. This difference is important when you want to ensure that allocated memory is initialized in a specific way.