When defining a structure in C, which keyword is used?
- class
- define
- struct
- type
In C programming, the keyword "struct" is used to define a structure. The "struct" keyword is followed by the structure name, and within the curly braces, you define the structure members or fields.
Why would a developer use pointers to structures instead of using structures directly?
- To add complexity to the code
- To improve program performance
- To save memory
- To simplify the code
Developers use pointers to structures to improve program performance. When you use pointers, you can manipulate data more efficiently and avoid creating redundant copies of structures, leading to better memory and performance optimization. It simplifies code by allowing you to pass structures by reference and make changes directly to the original data. However, it can add complexity to the code, so careful usage is essential.
In C, if you want to ensure that all the data written to a file is physically stored, you can use the ______ function.
- fwrite()
- fflush()
- fseek()
- fsync()
The correct option is b) fflush(). This function flushes the output buffer, ensuring that all data is physically stored in the file.
What does a nested structure in C allow you to do?
- Create a structure inside another structure
- Define a function inside a structure
- Define a structure with no members
- Nest loops within a structure
In C programming, a nested structure allows you to create a structure inside another structure. This can be useful when you want to represent complex data structures, as it lets you organize related data even further, creating a hierarchical structure.
In C++, what is function overloading?
- Creating new functions with unique names for each
- Using different names for the same function with the same parameters
- Using the same name for a single function with different parameters
- Using the same name for different functions with different parameters
In C++, function overloading refers to using the same function name for different functions with different parameter lists. This allows you to perform similar operations with different data types.
In C, what is the effect of using pointers as function parameters with regards to pass by value and pass by reference?
- Pointers can only be used in pass by value scenarios.
- Pointers enable pass by reference.
- Pointers enable pass by value.
- Pointers have no impact on pass by value or pass by reference.
Using pointers as function parameters in C enables pass by reference. When a pointer to a variable is passed to a function, changes made to the variable within the function are reflected outside the function, similar to pass by reference.
The function ________ is used to close a file in C.
- fclose()
- close()
- endfile()
- fileclose()
The correct option is a) fclose(). This function in C is used to close the file associated with the specified file pointer.
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.
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.
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.
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.
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.