Pointers in C: when to use the ampersand and the asterisk?

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I'm just starting out with pointers,
and I'm slightly confused. I know & means the address of a
variable and that * can be used in front of a pointer variable
to get the value of the object that is pointed to by the pointer. But things work
differently when you're working with arrays, strings or when you're calling functions
with a pointer copy of a variable. It's difficult to see a pattern of logic inside all
of this.

When should I use
& and *?

Answer

You have pointers and
values:

int* p; // variable p is
            pointer to integer type

int i; // integer
            value

You turn a
pointer into a value with
*:

int i2
            = *p; // integer i2 is assigned with integer value that pointer p is pointing
            to

You turn a value
into a pointer with
&:

int*
            p2 = &i; // pointer p2 will point to the address of integer
            i

Edit:
In
the case of arrays, they are treated very much like pointers. If you think of them as
pointers, you'll be using * to get at the values inside of them
as explained above, but there is also another, more common way using the
[]
operator:

int a[2]; // array of
            integers
int i = *a; // the value of the first element of a
int i2 =
            a[0]; // another way to get the first
            element

To
get the second element:

int a[2];
            // array
int i = *(a + 1); // the value of the second element
int i2
            = a[1]; // the value of the second
            element

So the
[] indexing operator is a special form of the
* operator, and it works like
this:

a[i] == *(a + i);
            // these two statements are the same
            thing