You're optimizing a program for memory usage. What considerations would you take into account when deciding between using character arrays and string literals?
- Character arrays consume less memory than string literals, making them a better choice for memory optimization.
- Character arrays provide better performance due to reduced memory overhead.
- String literals are less efficient in terms of memory usage compared to character arrays.
- String literals are more memory-efficient, as they share storage and avoid duplicating string data.
When optimizing a program for memory usage, you would consider using character arrays over string literals because character arrays generally consume less memory. String literals can lead to duplicate storage, whereas character arrays allow more control over memory usage.
What happens when you perform pointer arithmetic on a pointer to a data type other than 'char'?
- It generates a compilation error
- It increments the pointer by one byte
- It results in undefined behavior
- It returns the size of the data type in bytes
When you perform pointer arithmetic on a pointer to a data type other than 'char,' it results in undefined behavior. This is because the pointer arithmetic depends on the size of the data type, and it may lead to accessing memory incorrectly.
What is the main purpose of using pointers in a C program?
- To allocate memory dynamically
- To create functions
- To perform arithmetic operations
- To store multiple values in a single variable
Pointers in C are used to allocate memory dynamically, which is a crucial feature for managing data efficiently. They allow you to allocate memory as per the program's requirements.
The #undef directive is used to ________ a macro defined by #define.
- declare
- initialize
- redefine
- remove
The #undef directive is used to remove a macro definition created by #define. It essentially "undefines" the macro, making it no longer available for use.
In C, the function ________ is used to allocate memory for an array of elements and initialize them to zero.
- calloc()
- free()
- malloc()
- realloc()
In C, the function calloc() is used to allocate memory for an array of elements and initialize them to zero. Unlike malloc(), it automatically initializes the memory to zero, making it useful for arrays. realloc() is used to resize memory, and free() deallocates memory.
Why might you choose to use an enumeration instead of a series of #define statements for constants?
- #define statements are faster to evaluate
- Enumerations are more memory-efficient
- Enumerations cannot be used for constants
- Enumerations provide type checking
You might choose to use an enumeration instead of a series of #define statements for constants because enumerations provide type checking, making your code more robust and error-prone. #define statements are simple text replacements and do not offer type safety.
The ________ keyword in C suggests to the compiler to use a CPU register for the variable to optimize access time.
- const
- register
- static
- volatile
The 'register' keyword in C suggests to the compiler to use a CPU register for the variable to optimize access time, which can lead to faster variable access.
What is a variable declared within a block or a function known as?
- Dynamic variable
- Local variable
- Private variable
- Public variable
A variable declared within a block or a function is known as a local variable, and its scope is limited to that specific block or function.
What is the difference between stderr and stdout in the context of buffering?
- stderr is unbuffered, while stdout is line-buffered by default.
- stderr is line-buffered, while stdout is unbuffered.
- stderr is fully buffered, while stdout is line-buffered.
- stderr is fully buffered, while stdout is unbuffered.
The correct option is "stderr is unbuffered, while stdout is line-buffered by default." stderr is typically unbuffered, meaning that data is immediately written to the output, while stdout is line-buffered, meaning that it is buffered until a newline character is encountered.
You are working on a program that processes large datasets. Why might you choose to use pointers and pointer arithmetic to traverse the data?
- To enable dynamic data structures
- To enhance data access speed
- To improve memory efficiency
- To simplify code readability
Using pointers and pointer arithmetic can significantly improve data access speed. It allows direct memory access, reducing the need for complex data structures and enhancing performance in large dataset processing.