Zeroing out member arrays in a Structure

[manofsteel972]

I am making a Black Jack card game and I am using a structure to hold the player cards and information however when I go to redeal a new hand i need to zero out the old hand otherwise it just keeps adding cards. I am trying to use memset to zero out just the particular member variable arrays but for some reason it still just keeps the same values from the previous hand.

struct Players
{
	char name[MAX_PLAYERS][80];
	char *card[MAX_PLAYERS][MAX_HAND];	//card names
	char *suit[MAX_PLAYERS][MAX_HAND];	//card suits
	int value[MAX_PLAYERS][MAX_HAND];	//point value of cards
	int index[MAX_PLAYERS][MAX_HAND];	//index number of cards in hand
	int total_cards[MAX_PLAYERS];	//total number of cards in hand
	int Aces[MAX_PLAYERS];  //number of Aces in hand
	int Money[MAX_PLAYERS];  //total winnings 
	int Bet[MAX_PLAYERS];  //current bet amount
};

code i am using to try to zero out the member arrays

		memset(&players.Aces ,0,sizeof(players.Aces[MAX_PLAYERS] ));
		memset(&players.Bet  ,0,sizeof(players.Bet[MAX_PLAYERS] ));
		memset(&players.card  ,0,sizeof(players.card[MAX_PLAYERS][MAX_HAND]  ));
		memset(&players.index  ,0,sizeof(players.index[MAX_PLAYERS][MAX_HAND]  ));
		memset(&players.suit  ,0,sizeof(players.suit[MAX_PLAYERS][MAX_HAND]  ));
		memset(&players.total_cards ,0,sizeof(players.total_cards[MAX_PLAYERS]));
		memset(&players.value ,0,sizeof(players.value[MAX_PLAYERS][MAX_HAND] ));

[Dave Evans]

put the following in your main() (or some place that knows what players and MAX_PLAYERS are:

 printf("sizeof(players.Aces[MAX_PLAYERS]) = %d\n", 
      sizeof(players.Aces[MAX_PLAYERS]));

This tells the number of bytes of memory that an int takes in your system. (Not very useful in your context.)


Furthermore, instead of memset, just use loops:

int i;

for (i = 0; i < MAXPLAYERS; i++) {
  players.Aces[i] = 0;
  players.Bet[i] = 0;
  /* you get the idea, I hope */
}

Simpler, easier to read and understand; guaranteed portable.

Dave

[manofsteel972]

Thanks for the info Dave. (is memset not portable?) I found I wasn't passing a pointer properly so the deck pointer was not incrementing it just started over and that is why they cards were not changing. Also I removed the [MAX_PLAYERS] from the memset since I was trying to get the size of the array not the size of the array element and it works fine now.

[Dave Evans]

Originally posted by manofsteel972
(is memset not portable?)

Yes it is part of the C Standard Library, and, therefore is portable.

Oh, well, I'm just predjudiced against direct memory manipulation instead of commonly used control structures.

Regards,

Dave

[Magos]

To save some space, memset the whole structure in 1 step:

memset(&players, 0, sizeof(Players));