A pointer to a function in C is declared using the syntax ________.
- *func_ptr
- func()ptr
- func_ptr()
- ptr_func
In C, to declare a pointer to a function, you use the syntax "return_type (*pointer_name)(arguments)." This allows you to call a function through the pointer.
Failing to release a memory block with ________ before the program terminates can result in a memory leak.
- calloc()
- free()
- malloc()
- realloc()
Failing to release memory with the "free()" function in C can result in a memory leak, where the allocated memory is not properly deallocated, causing the program to consume more memory than necessary.
Consider a scenario where a program needs to store a character read from a file. Which data type would be appropriate for this?
- char
- double
- float
- int
To store a character read from a file in C, the appropriate data type is 'char' as it can represent individual characters effectively.
In C, function pointers are useful when you want to choose at runtime which ________ to execute.
- Data structure
- Function or behavior
- Memory allocation
- Variable
Function pointers in C allow you to select and call functions dynamically at runtime based on the desired behavior, enhancing the flexibility of your code.
In a C program, you notice that data written to a file is not immediately visible on the disk. What could be a reason for this delay?
- Buffering
- File format mismatch
- File permissions issue
- Insufficient disk space
Buffering is a common reason for a delay in writing data to a file in C. The system may buffer data before writing it to disk for efficiency. This buffering can cause a delay in making the data visible on the disk.
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.
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.