What exactly is the purpose of the (asterisk) in pointers?

Question

I'm new to programming and I'm trying to wrap my head around the idea of 'pointers'.

---

int main()
{
    int x = 5;
    int *pointerToInteger = & x;
    cout<<pointerToInteger;

}

Why is it that when I cout << pointerToInteger; the output is a hexdecimal value, BUT when I use cout << *pointerToInteger; the output is 5 ( x=5).

Answer 1

One way to look at it, is that the variable in your source/code, say

int a=0;

Makes the 'int a' refer to a value in memory, 0. If we make a new variable, this time a (potentially smaller) "int pointer", int *, and have it point to the &a (address of a)

int*p_a=&a; //(`p_a` meaning pointer to `a` see Hungarian notation)

Hungarian notation wiki

we get p_a that points to what the value &a is. Your talking about what is at the address of a now tho, and the *p_a is a pointer to whatever is at the &a (address of a).

This has uses when you want to modify a value in memory, without creating a duplicate container.

p_a itself has a footprint in memory however (potentially smaller than a itself) and when you cout<<p_a<<endl; you will write whatever the pointer address is, not whats there. *p_a however will be &a.

p_a is normally smaller than a itself, since its just a pointer to memory and not the value itself. Does that make sense? A vector of pointers will be easier to manage than a vector of values, but they will do the same thing in many regards.