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.
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 is the impact of using inline functions on the size of the compiled binary?
- Decreases binary size
- Depends on compiler optimization
- Increases binary size
- No impact on binary size
Inline Functions are a feature in C/C++ that help reduce function call overhead. They can lead to smaller binary sizes due to inlining, where the function's code is inserted directly at the call site, reducing the need for a separate function call.
To resize a previously allocated memory block, the function ________ is used in C.
- calloc()
- free()
- malloc()
- realloc()
To resize a previously allocated memory block in C, the function realloc() is used. It allows you to change the size of the memory block while preserving the existing data. malloc() and calloc() are used for initial memory allocation, and free() deallocates memory.
How can function pointers be used to implement callbacks in C?
- Function pointers are not used for callbacks
- Function pointers are used for dynamic linking
- Function pointers are used to implement recursion
- Function pointers can be used to pass a function as an argument to another function
Function pointers in C can be used to implement callbacks. By passing a function pointer as an argument to another function, you can dynamically specify the function to be called, enabling flexibility in callback implementations.