Pointers – Multiple Choice Questions (MCQs)

1. 25. What are the potential problems caused by dangling pointers?

   • A. Program crashes
   • B. Memory leaks
   • C. Incorrect program behavior
   • D. All of the above

2. 26. What is memory leakage in the context of pointers and dynamic memory allocation?

   • A. Failure to allocate memory
   • B. Failure to free dynamically allocated memory
   • C. Accessing memory out of bounds
   • D. Incorrect pointer arithmetic

3. 27. Which standard library function is used to allocate a block of memory dynamically in C?

   • A. malloc()
   • B. free()
   • C. sizeof()
   • D. typedef()

4. 28. Which standard library function is used to release a dynamically allocated block of memory in C?

   • A. malloc()
   • B. free()
   • C. sizeof()
   • D. typedef()

5. 29. What is the purpose of the `sizeof()` operator when used with a pointer?

   • A. It returns the size of the data type pointed to by the pointer
   • B. It returns the size of the pointer itself
   • C. It returns the address stored in the pointer
   • D. It returns the number of elements the pointer can point to

6. 30. What is the difference between `ptr++` and `(*ptr)++` if `ptr` is an integer pointer?

   • A. `ptr++` increments the pointer address by the size of an integer
   • B. `(*ptr)++` increments the value pointed to by the pointer
   • C. `ptr++` increments the value
   • D. `(*ptr)++` increments the address

7. 31. What is the output of the following code? `int a = 10; int *ptr = &a; printf(\%d\"",*ptr);`"""

   • A. 10
   • B. The address of a
   • C. Error
   • D. 0

8. 32. What is the output of the following code? `int arr[] = {1, 2, 3}; int *ptr = arr; printf(\%d\"",*(ptr + 2));`"""

   • A. 1
   • B. 2
   • C. 3
   • D. Error

9. 33. What is the output of the following code? `int a = 5; int *ptr = &a; *ptr = 15; printf(\%d\"",a);`"""

   • A. 5
   • B. 15
   • C. The address of a
   • D. Error

10. 34. What is the output of the following code? `int x = 20; int *p = &x; int **q = &p; printf(\%d\"",**q);`"""

    • A. The address of x
    • B. The address of p
    • C. 20
    • D. Error

11. 35. What is the relationship between pointer arithmetic and array indexing?

    • A. `ptr[i]` is equivalent to `*(ptr + i)`
    • B. Pointer arithmetic only works with character pointers
    • C. Array indexing is faster than pointer arithmetic
    • D. There is no relationship

12. 36. What is the purpose of using pointers with functions?

    • A. To modify the original variables passed to the function
    • B. To pass large data structures efficiently
    • C. To implement call by reference
    • D. All of the above