Pointers in c language: 18 MCQs with answers

To store the memory address of a variable

A pointer is a variable that holds the memory address of another variable, enabling indirect access.

*

The asterisk (*) in a declaration indicates that the variable is a pointer to a certain type.

Returns the memory address of the variable

The address-of operator (&) yields the memory address where the variable is stored.

10

The dereference operator (*) accesses the value stored at the address held by the pointer, which is 10.

A pointer that points to no valid memory location

A null pointer (NULL) is a special value that indicates the pointer does not point to any valid memory location.

True

By definition, a pointer holds the address of a variable.

False

The dereference operator (*) accesses the value at the address, while the address-of operator (&) gets the address.

8

Changing the value at the address pointed to by p modifies the original variable a, so a becomes 8.

It causes undefined behavior, often a crash

Dereferencing a null pointer is undefined behavior and typically results in a segmentation fault or crash.

Performing arithmetic operations on the pointer's address

Pointer arithmetic involves adding or subtracting integers to/from a pointer, which moves the pointer by multiples of the size of the pointed-to type.

The address of the next integer element

Pointer arithmetic scales by the size of the type, so p+1 points to the next integer in the array.

An array name is a constant pointer to its first element

The name of an array acts like a constant pointer to the first element, and pointer arithmetic can traverse the array.

A pointer that stores the address of another pointer

A pointer to a pointer (e.g., int **pp) stores the address of a pointer variable, allowing multiple levels of indirection.

Pass the address of the variable using &

Passing the address (&var) allows the function to dereference the pointer and modify the original variable.

They allow direct memory access and efficient manipulation

Pointers provide direct memory access, enabling efficient array processing, dynamic memory allocation, and data structures.

Using the free() function

The free() function is used to deallocate memory previously allocated by malloc(), calloc(), or realloc().

A pointer that points to a function's code

A function pointer stores the address of a function, allowing it to be called indirectly.

A pointer that points to memory that has been freed or deallocated

A dangling pointer points to memory that has been freed, leading to undefined behavior when dereferenced.