C-Volution (Intermediate)

What is the output of the following code #include int main() { int x = 5; int *p = &x; *p = *p + 10; printf("%d\n", x); return 0; }

• 5

• 10

• 15

• Error

Which of the following is NOT a valid way to dynamically allocate memory?

• malloc()

• calloc()

• realloc()

• alloc()

What is the primary difference between malloc() and calloc()?

• malloc() initializes allocated memory to zero, calloc() does not.

• calloc() allocates memory for a single element, malloc() for multiple.

• malloc() allocates memory in bytes, calloc() in number of elements.

• There is no difference.

What is a dangling pointer?

• A pointer that points to a memory location that has been freed.

• A pointer that has not been initialized.

• A pointer that points to a null value.

• A pointer that points to an invalid memory address.

What is the output of the following code? #include int main() { char str[] = "Hello"; printf("%lu\n", sizeof(str)); return 0; }

• 5

• 6

• 7

• Error

Which of the following is the correct way to declare a function pointer?

• int (*func)(int, int);

• int *func(int, int);

• int func(int, int);

• int *(func)(int, int);

What does the const keyword signify when used with a pointer?

• The pointer cannot be changed.

• The value pointed to by the pointer cannot be changed.

• Both the pointer and the value pointed to cannot be changed.

• It has no effect.

What is the output of the following code? #include void swap(int *a, int *b) { int temp = *a; *a = *b; *b = temp; } int main() { int x = 5, y = 10; swap(&x, &y); printf("x = %%d, y = %%d\n", x, y); return 0; }

• x = 5, y = 10

• x = 10, y = 5

• x = 5, y = 5

• x = 10, y = 10

What is the purpose of a header file in C?

• To define the main function.

• To declare function prototypes and other pre-defined elements.

• To store the compiled code.

• To contain comments.

Which preprocessor directive is used to include a header file?

• #include

• #define

• #ifdef

• #ifndef