Quiz for Pointers to pointers

Q1: What is a pointer to a pointer in C?

A. A variable that stores the address of another pointer B. A variable that stores the address of an integer C. A variable that stores the address of a function D. A variable that stores the value of another variable

Q2: Which syntax correctly declares a pointer to a pointer to int?

A. int **ptr; B. int *ptr; C. int ***ptr; D. pointer **ptr;

Q3: If int x = 5; int *p = &x; int **pp = &p;, what does **pp return?

A. 5 B. Address of x C. Address of p D. Garbage value

Q4: What is stored in a pointer to pointer variable?

A. Address of another pointer B. Address of an array C. Value of an integer D. Address of a constant

Q5: Which of the following can be used to dynamically allocate a 2D array using pointers to pointers?

A. malloc with int** B. malloc with int* C. calloc with int D. Only arrays

Q6: How to access the value pointed by a pointer to pointer?

A. *pp B. **pp C. &pp D. pp

Q7: If p2 is a pointer to p1 and p1 points to x, which gives the value of x?

A. *p2 B. **p2 C. p2 D. &p2

Q8: Can we have a pointer to a pointer to a pointer?

A. Yes B. No C. Only in arrays D. Only in structs

Q9: What is the level of indirection in int ***ptr?

A. 1 B. 2 C. 3 D. 4

Q10: If int x=10; int *p=&x; int **pp=&p; what is the type of pp?

A. int* B. int C. int** D. pointer

Q11: Which of these can be used to pass a pointer to a function to modify the original pointer?

A. Pointer to pointer B. Integer C. Array D. Structure

Q12: What happens if you dereference a pointer to pointer with one * only?

A. It gives the address of the final value B. It gives the final value C. It gives garbage D. It gives compilation error

Q13: What is the correct format specifier to print the address stored in a pointer to pointer?

A. %p B. %d C. %u D. %f

Q14: In memory management, a pointer to pointer is mostly used for?

A. Handling dynamic arrays B. Handling constants C. Handling macros D. Handling keywords

Q15: If int **pp; what does sizeof(pp) return?

A. Size of a pointer B. Size of an integer C. Size of a pointer to int D. Size of a pointer to pointer

Q16: Which of these is a valid initialization of a pointer to pointer?

A. int **pp = NULL; B. int **pp = 0; C. int **pp; D. All of the above

Q17: What is the output? int x=3; int *p=&x; int **pp=&p; printf("%d", **pp);

A. 3 B. Address of x C. Address of p D. Garbage

Q18: What happens if a pointer to pointer is not initialized?

A. It contains garbage B. It contains zero C. It contains NULL D. It crashes

Q19: What is the difference between int *p and int **pp?

A. One points to int, other points to pointer to int B. Both point to int C. One points to address, other points to value D. No difference

Q20: Which is true about pointer to pointer?

A. They can have multiple levels B. They cannot point to NULL C. They always store integer addresses D. They are slower than arrays