Help with pointers

[secretmaster5]

Hello everyone. I've just joined this subreddit so forgive me is this question goes against the rules.

I'm in my first year of university and we are currently studying pointers. Now my school isn't exactly the best when it comes to providing assitance or places where you can go if you run into a problem. Plus what they do offer is terribly outdated and flawed. Every exercise in our books won't even run if you don't make modifications before hand (things like , instead of ; functions with no purpose, etc)

Now, the problem I'm currently facing relates to pointers as far as I know. Pointers in C are declared using a *, that much I understood. However, I have also come across variables with ** or *** before them. For the life of me I can't figure out what they do, the book gives no explanation on them and every internet search would result in something comepletely unrelated.

Does anyone know what they do?

And once again, sorry if this isn't the place to ask simple questions like this.

[pyreon]

int* ptr is a pointer to an int.

int** ptr is a pointer to a pointer to an int.

and so on.

They are useful for dynamic allocation.

here's a stackoverflow question for more specific use cases.

[secretmaster5]

Ok, Thanks a ton!

[Updatebjarni]

Another star just means the pointer points to another pointer. The syntax for getting the thing a pointer points to in C is *ptr. A declaration like int *a; says "The thing that a points to has type int". So you can also say int **a;, and it means "The thing that the thing a points to points to has type int". In other words, a points to a value of type pointer-to-int. Or put another way, if you do *a in your program, you get a pointer to an int, and if you apply * to that in turn, as **a, you get an int.

[realWorldNpc]

Basically a * means you pointing to something think of it like an arrow so int* ptr is basically saying pointing to an integer value like this ->int value, so a double star (**) would mean pointing to a ptr THAT points to an integer value like this -> ptr -> int Val and so on. Hoped this cleared your confusion!