C is like chinese to me but i got to work with some code
struct Message {
unsigned char state;
};
char state [4][4] = { "OFF", "ON", "IL1", "IL2" };
This is a simple server that receives a message. The Struct part of it is obvious, but then theres that char array thing. Does this say theres 4 different char arrays, each containing 4 chars? What exactly is going on here? I know this sounds stupid but I cant figure it out.
It means that state is an array of 4 char arrays, each of them is an array of 4 char, and they are initialized with the values "OFF\0", "ON\0", "IL1\0" and "IL2\0"
+----+----+----+----+
state => |OFF |ON |IL1 |IL2 |
+----+----+----+----+
^state[0]
^state[1]
^state[2]
^state[4]
\0 at the end of each word, as in C string there is another hidden character, \0, called the null terminator that signals the end of the string, and you need to have space for it too. en.wikipedia.org/wiki/Null-terminated_stringIt's a two-dimensional array. It creates an array of 4 elements, each of which is an array of 4 char.
Does this say theres 4 different char arrays, each containing 4 chars?
That's exactly right: state is an array of four char sub-arrays.
Each sub-array is four chars long. The corresponding string literal ("OFF" etc) is padded with NULs to four characters, and copied into the sub-array.
char state[4][4] declared at the end is a 2 dimensional array having 4 rows with 4 columns in each row. The values you have assigned will be stored into positions state[0][0], state[0][1], state[0][2], state[0][3].
In C, you deal with strings as char*, or arrays of char. Therefore, when you have an array of strings, you have an array of an array of chars.
C is like chinese to meisn't this a top phrase for IT college drop-outs?