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.
Which operator is used to check if two values are equal?
- !=
- =
- ==
- ===
In C, the '==' (double equals) operator is used to check if two values are equal. It is a comparison operator, while '=' is an assignment operator. Confusing these can lead to unintended consequences, making it crucial to understand their distinct purposes in programming.
What string handling function is used to concatenate two strings in C?
- sprintf()
- strcat()
- strcmp()
- strcpy()
In C, the strcat() function is used to concatenate two strings. It appends the characters of the second string to the end of the first string.
In a project involving real-time systems, you notice that different modules use different naming conventions for the same data type. What feature of C can help maintain consistency across modules?
- Typedef
- Namespaces
- Code comments
- Function pointers
Option A, "Typedef," is the most suitable choice in this context. By using typedef, you can create consistent, user-friendly names for data types, which helps maintain a unified naming convention across modules in a project. This consistency enhances code readability, reduces errors, and simplifies maintenance. Namespaces are not a feature in C, and other options do not directly address naming convention consistency. Understanding how to use typedef effectively is essential for creating a consistent codebase in C.
How can you redirect error messages in a C program to a file instead of displaying them on the console?
- stderr_redirect()
- errorToFile()
- file_error()
- freopen()
The correct option is freopen(). This function can be used to redirect standard error (stderr) to a file. By using freopen("error.log", "w", stderr), error messages will be written to the specified file instead of the console.
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.