Initializing a struct in C - c

Question

Im having trouble initialising structures (well doing everything actually, but structures first). The struct is first made in a header as follows
typedef enum cell
{
BLANK, RED, CYAN
} Cell;
#define NAMELEN 20
typedef struct player
{
char name[NAMELEN + NULL_SPACE];
Cell token;
unsigned score;
} Player;
void initFirstPlayer(Player * player);
void initSecondPlayer(Player * player, Cell token);
#endif
=======================================================================
and I tried to initialise it here
void initFirstPlayer(Player * player)
{
int randNo = rand() % 2;
if (randNo == 0) {
token = RED;
}
else() {
token = CYAN;
}
player ; p1 = {
"placeholder",
token,
0,
}
}
void initSecondPlayer(Player * player, Cell token)
{ }
What is the correct way to initialise this player struct?

Answer 1

I suspect this should work for you. Use a generic initPlayer function. Use that to allocate memory for the player and set the initial values. Be sure to also include a freePlayer function where you free() the player when you're done.
#include <stdlib.h>
#include <string.h>
Player* initPlayer()
{
Player* player = malloc(sizeof(Player));
int randNo = rand() % 2;
if (randNo == 0) {
player->token = RED;
}
else {
player->token = CYAN;
}
const char* initName = "placeholder";
strcpy(player->name, initName);
player->score = 0;
return player;
}
void freePlayer(Player* p)
{
free(p);
}
The way you'd use this would be like so:
int main()
{
Player* p1 = initPlayer();
Player* p2 = initPlayer();
play(p1, p2);
freePlayer(p1);
freePlayer(p2);
}

Answer 2

Assuming you have at least C99 support, so that compound literals and designated initializers are available to you, then you can use:
void initFirstPlayer(Player *player)
{
*player = (Player){ .token = rand() % 2 ? CYAN : RED,
.score = 0,
.name = "placeholder"
};
}
This does a structure assignment to the variable whose address is passed to the function. It compresses it all into one statement; you can split it out into several if you wish. This is an occasion where the ternary ? : operator is useful. You might prefer (rand() % 2) with the extra parentheses; I'd probably add them as often as I'd omit them.
The compound literal comes from (typename){ ...initializer for typename... }.
The designated initializers are the .member = value notations.
If you're stuck with C90 support, you have to work harder, perhaps creating a local variable with the correct information and then doing the structure assignment.
void initFirstPlayer(Player *player)
{
Player p1 = { "placeholder", rand() % 2 ? CYAN : RED, 0 };
*player = p1;
}
Now the onus is on you to list the initializers in the correct sequence.

Answer 3

Another way is to receive the player you want to inicialize as parameter:
void initPlayer(Player* player)
{
int randNo = rand() % 2;
if (randNo == 0) {
player->token = RED;
}
else {
player->token = CYAN;
}
const char* initName = "placeholder";
strcpy(player->name, initName);
player->score = 0;
}
int main() {
Player p1;
initPlayer(&p1);
}
You can have an array of players or allocate dinamically with malloc.