指向C中的结构表的指针

Question

I don't understand some piece of code in C , and couldn't find any similar question, so I hope you'll help me. I have a struct table defined like this:

struct my_struct {
  struct other_struct some_struct[N];
  char some_char;
  ..
} my_struct[N];

In another function:

struct my_struct *ms;

And then is the part I don't understand:

ms = &my_struct[0];

How can I interpret this line?

Answer 1

ms is a pointer to the struct my_struct . It contains address of a struct my_struct variable. Here we assign to ms the already declared struct my_struct array's (also name my_struct ) 0-th element's address.

& - address of operator. Which basically returns the address of a variable.

Now you can access my_struct[0] via ms .

Equivalently

ms->some_char = 'A' is same as my_struct[0].some_char='A' . To give a small example I can simplify this way.

struct a{
  int z;
};

struct a array[10]; // array of 10 `struct a`

struct a* ptr = &array[0]; // ptr contains the address of array[0].

Now we can access array[0] via pointer ptr .

And ms is just a pointer to struct not pointer to a table of struct as you have mentioned in the question heading.