What is the purpose of the strcpy function in C?
- Allocates memory for a new string
- Calculates the length of a string
- Compares two strings
- Copies one string to another
The strcpy function in C is used to copy one string into another. It does not calculate the length, compare strings, or allocate memory.
When a file is opened in ________ mode, it is opened for both reading and writing in binary format.
- binary_rw
- r+b
- rb+
- rw
Opening a file in r+b mode in C allows for both reading and writing operations in binary format. The 'r' stands for read, and the 'b' indicates binary mode, making it suitable for combined read and write tasks.
In C, a pointer is a variable that stores the ________ of another variable.
- Address
- Function
- Size
- Value
In C, a pointer stores the address of another variable. Pointers are used to work with memory addresses, allowing you to access and manipulate the data stored at that location.
In a large software project, certain code needs to be compiled only for debugging purposes. How can preprocessor directives be used to achieve this?
- By using 'ifdef' and 'ifndef'
- By using 'for' loops
- By using 'switch' statements
- By using 'while' loops
Preprocessor directives like 'ifdef' and 'ifndef' can conditionally include or exclude sections of code based on predefined conditions. This is often used to include debugging code only during debugging builds. Options b, c, and d are not related to preprocessor directives.
You're developing a function that modifies an array of integers. To ensure that the original array is not altered, how should the array be passed to the function?
- Pass a copy of the array
- Pass a pointer to the array
- Pass by reference
- Pass by value
To ensure that the original array is not altered, you should pass a pointer to the array to the function. This way, the function can work with the original data without making a copy of the array. Pass by reference typically involves languages like C++ and is not a direct concept in C. Pass by value would create a copy of the array, which is not the desired behavior. Passing a copy of the array would have the same effect as passing by value.
To allocate memory dynamically and initialize it to a specific value, the ________ function can be used in C.
- calloc()
- free()
- malloc()
- realloc()
In C, the "calloc()" function is used to dynamically allocate memory and initialize it to a specific value. It takes two arguments for the number of elements and the size of each element, allocating memory for an array.
An array name in C essentially acts as a ________ to the first element of the array.
- container
- pointer
- reference
- variable
An array name in C essentially acts as a reference to the first element of the array, making it easy to access.
In C, a structure member with a specified width is known as a ________.
- Bit Field
- Conditional Statement
- Enum Member
- Pointer Variable
In C, a structure member with a specified width is known as a bit field, allowing you to optimize memory usage by using a specific number of bits.
In C, the ________ function is used to write a string to a file.
- write()
- fputstring()
- fwrite()
- fputs()
The correct option is fputs(). This function is used to write a string to a file in C, providing a convenient way to output a sequence of characters to the specified file.
How can you determine the size of an array in C?
- By counting the number of elements
- By using the 'size' function
- Using the 'length' keyword
- Using the 'sizeof' operator
You can determine the size of an array in C by using the 'sizeof' operator. It returns the size in bytes, so dividing it by the size of one element gives you the number of elements in the array.