Memory and Pointers

Question 1

What is a pointer?

Answer 1

A pointer is a variable that contains an
address in memory.

Question 2

What is the size of a pointer in 64 bit architecture?

Answer 2

8 bytes

Question 3

Do functions like strcpy, strcat, strstr allocate memory for you?

Answer 3

No, you need to use malloc to allocate memory before

Question 4

How to print a pointer? In hexadecimal?

Answer 4

printf(“ptr=%ld\n”,(unsigned long)&buff[5])

printf(“ptr=0x%lx\n”,(unsigned long) &buff[5])

Question 5

When you increment a pointer to an integer how many units does it increase?

Answer 5

4, bc an int is 4 bytes

Question 6

Why is using pointers efficient in coding?

Answer 6

It doesn’t require indexing, indexing in arrays (int[i]) requires multiplication.

Question 7

What are some advantages of Pointer based arrays?

Answer 7

● You don’t need to know in advance the size of the array (dynamic memory allocation)
● You can define an array with different row sizes
● A jagged array uses multiple small blocks instead of one large block of memory.

Question 8

What is Polymorphism?

Answer 8

Being able to use the same function with arguments of different types.

Question 9

What are pointers to functions useful for?

Answer 9

Polymorphism