Question

I have few questions:

1) why when I created more than two dynamic allocated variables the difference between their memory address is 16 bytes. (I thought one of the advantages of using dynamic variables is saving memory, so when you delete unused variable it will free that memory); but if the difference between two dynamic variables is 16 bytes even using a short integer, then there a lot of memery that I will not benifit .

2) creating a dynamic allocated variable using new operator.

int x;
cin >> x;
int* a = new int(3);
int y = 4;
int z = 1;

In the e.g above. what is the flow of execution of this program. is it gonna store all variable likes x,a,y and z in the stack and then will store the value 3 in the address that a points to?

3) creating a dynamic alloated array.

int x;
cin >> x;
int* array = new int[x];
int y = 4;
int z = 1;

and the same question here.

4) does the size of the heap(free scope) depend on how much of memory im using in the code area,the stack are, and the global area ?

Answer 1

1. Storing small values like integers on the heap is fairly pointless because you use the same or more memory to store the pointer. The 16 byte alignment is just so the CPU can access the memory as efficiently as possible.
2. Yes, although the stack variables might be allocated to registers; that is up to the compiler.
3. Same as 2.
4. The size of the heap is controlled by the operating system and expanded as necessary as you allocate more memory.