What does it mean when a * follows the type name in C++?

Question

I am a Java guy trying to learn C++.

I came across some code where following the type name, there is a *. For example:

char* socialNum[125][9];

and

CSampleDoc* pDoc = GetDocument();

What does the star mean?

if you see `*` in C/C++, it's generally either multiplication, or a pointer. in this case, pointer. — Marc B, Oct 20 '13 at 21:32
I respectfully suggest that if you're trying to learn basic C++ syntax, do so with a [good book](http://stackoverflow.com/questions/388242/the-definitive-c-book-guide-and-list), rather than via Stack Overflow. — Oliver Charlesworth, Oct 20 '13 at 21:32
@OliCharlesworth I was using a book but I was constantly skipping since so much is the same as in Java. It was hard to find the points that I didn't already know — CodyBugstein, Oct 20 '13 at 21:34
@Imray: I suggest skipping back to the start. Other than superficialities, there are very few similarities between Java and C++. — Oliver Charlesworth, Oct 20 '13 at 21:35
Don't take this the wrong way, but before you start asking "what does the `&` mean" and "what does the `&&` mean" and "what does the `virtual` mean", could you just grab a C++ text book and read it for a week? — Kerrek SB, Oct 20 '13 at 21:37
Get a better book, or be a bit more diligent in reading the one you have. It is *critical* that you understand pointers, and you won't get a very complete understanding from SO posts. — Hot Licks, Oct 20 '13 at 23:12
You should accept either @Martijn Courteaux 's answer or mine :) — Chris Cirefice, Oct 21 '13 at 22:37

Martijn Courteaux · Accepted Answer · 2013-10-20T21:44:54.620

2

That means that the variable is a pointer.

int myInt = 4;
int *myPointer = &myInt;

Now, myPointer points to the integer myInt. Pointing to something is basically holding the memory address of that something.

Since you said you come from Java, this in Java:

MyClass obj = new MyClass(); // obj is a reference (or pointer)

would be equivalent with this in C++:

MyClass *obj = new MyClass(); // obj is here a pointer as well.

// and once you are done with obj, don't forget to free the memory:
delete obj;

edited Oct 20 '13 at 21:44

answered Oct 20 '13 at 21:32

Martijn Courteaux

2

He has a Java background. You should show him how to `delete` stuff first. – Sebastian Graf Oct 20 '13 at 21:42

score 0 · Answer 2 · answered Oct 20 '13 at 21:34

0

* means it is a pointer to a piece of data.

Take, for example, these:

int *myInt;
char *myChar;
MyClass *objectOfClass;

All of these are pointers to the data in memory. The value of the pointer is an int, which is the address (location) in memory of that data.

answered Oct 20 '13 at 21:34

Chris Cirefice

Does it matter if the `*` precedes the variable name or follows it? – CodyBugstein Oct 20 '13 at 21:34
Pointers(*) and references(&) must precede the variable name. – RealDeal_EE'18 Oct 20 '13 at 21:35
You can declare it as `int* myInt` or `int *myInt`, but you *cannot* declare it as `int myInt*`. See @criticalSeleciton's comment. – Chris Cirefice Oct 20 '13 at 21:36

2 Answers2