when you declare a static variable in c

Question

when you are declaring static variables in C,

say you wrote a program as such:

int *c;
void foo(){
    c = (int *) malloc (10*sizeof(int));
    c = &c[3];
    *c = *&c[3];
}

What does it mean to have *c? I mean I understand that * means that it points to something but what does *c do?

and also, why do you need to cast (int *) the return value of malloc()?

1. Study the basics of the language. It will take you decades to learn one trivial question at a time. 2. This has no relation to static variables. — juanchopanza, Feb 03 '15 at 07:01
do you recommend any website to learn the basics of c juanchopanza? — Peter Chung, Feb 04 '15 at 02:45

score 5 · Accepted Answer · edited May 23 '17 at 12:30

5

when you are declaring static variables in C

Not related to this question, or atleast to the code you've shown.

but what does *c do?

Assuming your question related to the statement *c = *&c[3];, it refers to the object at address held by c.

why did you have to cast (int *) in front of malloc?

You should not. Please do not cast the return value of malloc() [and family].

^{Note: You code snippet is very poor and bad practice, most likely to be invalid. c = &c[3]; obvious memory leak.}

edited May 23 '17 at 12:30

Community

answered Feb 03 '15 at 07:01

Sourav Ghosh

then what kind of variable is "int *c;"? – Peter Chung Feb 04 '15 at 01:57
@PeterChung `c` is a pointer to an `int`. – Quentin Jun 25 '15 at 11:39
Thank @Quentin for the fix and the answer to OP's latest question. (_Frankly speaking, I'm a bit surprised to see how/why I myself did not answer that. Confused._) – Sourav Ghosh Jun 25 '15 at 11:43

score 0 · Answer 2 · edited May 23 '17 at 12:13

0

I mean I understand that * means that it points to something but what does *c do?

The * does not always mean that it point to something. Example: If you write this:

int* c;

It means c is a pointer points to an int variable.

When you do like this:

int* c = &x;
*c = 5;

The second * is pointer c dereference.

edited May 23 '17 at 12:13

Community

answered Feb 03 '15 at 07:21

Trevor

2 Answers2