static buffer and non initialize static buffer

Question

Hi i am having 2 questions here

How do i store a hex value in a buffer, say for example 0x0a and 0x1F;
```
char buffer[2] = "0x0a 0x1F";
```
But this is not right method, It is giving size 10 instead of 2. Can any one suggest how can i proceed.
I have seen the array like this
```
char buffer[] = " static array";
```
In the structure also,
```
struct Point {
   char x[];
   char y[];
};
```
what does it mean? how much size it will take for compilation

Yes, but `"\x0a\x1F"` is three characters (remember the terminating `\0`) — Andreas Fester, Jan 15 '14 at 08:09
@Andreas Use as an initialization constant long strings it is not an error in C. — BLUEPIXY, Jan 15 '14 at 08:11
@BLUEPIXY Thanks, was not aware of that -http://stackoverflow.com/questions/6915737/char-array-initialization-dilemma ; so, the `\0` is simply not stored (which makes this approach of initializing a buffer at least questionable, IMHO...) — Andreas Fester, Jan 15 '14 at 08:19
@Andreas I understand that this is confusing, of course, but it was thought to be along the intention of the questioner. — BLUEPIXY, Jan 15 '14 at 08:25

paxdiablo · Answer 1 · 2014-01-15T08:49:43.807

For the first, assuming you really want a two-byte array rather than a three-byte string (including NULL terminator), you can use:

char buffer[] = {0x0a, 0x1f};

For the second, the easiest way to find out is to simply check:

sizeof(buffer)

or:

sizeof(struct Point)

although I'm pretty certain your structure definition will fail because char x[] is not a complete type. Current versions of the standard allow flexible array sizes at the end of structures but not the way you have it there.

Likely sizes of the two (once you declare struct Point with char x[5]) will be 14 (number of characters in " static array" including the NULL terminator) and 5 (the size of x itself (flexible array members tend not to take up space, they're more for allowing arbitrary extra space if the memory block is obtained by malloc, for example).

static buffer and non initialize static buffer

1 Answers1