Question about struct

[mikeman]

I've created my structure and now I'm trying to use a couple loops to sort through the data.

struct stats myPlayers[numPlayers]; // this is the struct

int sortStats(int numPlayers, struct stats myPlayers)
{
    int mostGoals = 0;
    int mostGoalsInd = 0;
    for (int i=0;i<numPlayers;i++)
    {
        if (myPlayers[i].goals > mostGoals)
        {
             mostGoals = myPlayers[i].goals;
             mostGoalsInd = myPlayers[i].ind;
        }
    }
    printf("%s scored the most goals this season with %d.\n", myPlayers[mostGoalsInd], mostGoals);

    return 0;
}

This is the function I've created to sort through the stats, as you my have guessed by the name. I want the function to sort through each member and for this example, determine which player has scored the most goals.

I'm getting an error at the if statement. I believe it's because it's not recognizing myPlayers[i].whatever. I think I need to have some sort of initialization to tell it where to pull from, which I thought is what I did when putting the struct stats myPlayers in the braces for the sortStats function. Where do you think I'm going wrong?

[Elysia]

I have a doubt.
The printf is way off. It's a struct, so you must pick a member to print, no?

[mikeman]

The printf is off, it was from a previous way I was trying to do something. I've commented it out.

The error at the if statement is the same for 3 lines, the line with the if statement, the line with the redefining mostGoals and the line redefining mostGoalsInd. The error is "subscripted value is neither array nor pointer"

[Elysia]

Of course!
You are passing a struct, not several, so there is no array to talk of!

[C_ntua]

int sortStats(int numPlayers, struct stats myPlayers[numPlayers])

or

int sortStats(int numPlayers, struct stats* myPlayers)

edit: This forum sure has some damn good support. It is not the first time I post something right before/after somebody else

[mikeman]

Hah! Thanks.

Now, when I call this function in main, I'm not sure what to put as the second argument.

sortStats(numPlayers, ??)

[Elysia]

Pass the name of the array.
Do not pass a array (ie myarray[n]), but the name of the array itself (ie myarray).

[mikeman]

Ok, so I would want to pass myPlayers in this instance, no?

Except myPlayers isn't defined in main. The structure is built in a function loadData. I tried declaring myPlayers and saying myPlayers = loadData(numPlayers, myStr) where myStr is the fileName, but it doesn't like that.

Sorry for having so many questions, but I sure do appreciate the help and timeliness

[mikeman]

This is the whole program as of right now, might give you more of an idea how I have it setup. I'm a bit new to all of this so it's probably not the best setup, but it's what I've been taught thus far and how my thought process is working at this point.

#include <stdio.h>
#include <stdlib.h>
int ind, gamesPlayed, goals, assists, points, plusMinus, penaltyMins, ppGoals, shGoals, gwGoals, otGoals, shots;
float shotPercent, shiftsPerGame, faceOffWinPercent;
char player[50];
char team[4];
char pos[2];
char timeOnIce[10];
int strPlayer = 0;
int strTimeOnIce = 0;


int getNumPlayers(char *fileName)
{
   int numPlayers = 0;
   FILE *fp;
   fp = fopen(fileName, "r");
   while (!feof(fp))
   {
        fscanf(fp, "%d %s %s %c %d %d %d %d %d %d %d %d %d %d %d %f %s %f %f", &ind, player, team, &pos, &gamesPlayed, &goals, &assists, &points, &plusMinus, &penaltyMins, &ppGoals, &shGoals, &gwGoals, &otGoals, &shots, &shotPercent, timeOnIce, &shiftsPerGame, &faceOffWinPercent);     
        numPlayers++;
   }
   printf("Number of players: %d\n", numPlayers+1); //add 1 to account for starting point of 0
   fclose(fp);
   return numPlayers;
}

struct stats
{
       int ind;
       char player[25];
       char team[4];
       char pos[2];
       int gamesPlayed;
       int goals;
       int assists;
       int points;
       int plusMinus;
       int penaltyMins;
       int ppGoals;
       int shGoals;
       int gwGoals;
       int otGoals;
       int shots;
       float shotPercent;
       char timeOnIce[6];
       float shiftsPerGame;
       float faceOffWinPercent;
};



int getLength(int numPlayers, char *fileName)
{
    FILE *fp;
    fp = fopen(fileName, "r");
    while (!feof(fp))
   {
        fscanf(fp, "%d %s %s %c %d %d %d %d %d %d %d %d %d %d %d %f %s %f %f", &ind, player, team, &pos, &gamesPlayed, &goals, &assists, &points, &plusMinus, &penaltyMins, &ppGoals, &shGoals, &gwGoals, &otGoals, &shots, &shotPercent, timeOnIce, &shiftsPerGame, &faceOffWinPercent);
        if (strlen(player) > strPlayer) strPlayer = strlen(player);
        if (strlen(timeOnIce) > strTimeOnIce) strTimeOnIce = strlen(timeOnIce);    
   }
    printf("The longest player name is %d characters long\n", strPlayer);
    printf("The time on ice vector needs %d characters\n", strTimeOnIce);
    fclose(fp);
    return 0;
}

int sortStats(int numPlayers, struct stats myPlayers[numPlayers])
{
    int mostGoals = 0;
    int mostGoalsInd = 0;
    int i = 0;
    for (i=0;i<numPlayers;i++)
    {
        if (myPlayers[i].goals > mostGoals)
        {
             mostGoals = myPlayers[i].goals;
             mostGoalsInd = myPlayers[i].ind;
        }
    }
    //printf("%s scored the most goals this season with %d.\n", myPlayers[mostGoalsInd], mostGoals);

    return 0;
}

int loadData(int numPlayers, char *fileName)
{
    int i = 0;
    FILE *fp;
    fp = fopen(fileName, "r");
    struct stats myPlayers[numPlayers];
         while (!feof(fp))
         {
            fscanf(fp, "%d %s %s %c %d %d %d %d %d %d %d %d %d %d %d %f %s %f %f", &ind, player, team, &pos, &gamesPlayed, &goals, &assists, &points, &plusMinus, &penaltyMins, &ppGoals, &shGoals, &gwGoals, &otGoals, &shots, &shotPercent, timeOnIce, &shiftsPerGame, &faceOffWinPercent);
            myPlayers[i].ind = ind;
            strcpy(myPlayers[i].player, player);
            strcpy(myPlayers[i].team, team);
            strcpy(myPlayers[i].pos, pos);
            myPlayers[i].gamesPlayed = gamesPlayed;
            myPlayers[i].goals = goals;
            myPlayers[i].assists = assists;
            myPlayers[i].points = points;
            myPlayers[i].plusMinus = plusMinus;
            myPlayers[i].penaltyMins = penaltyMins;
            myPlayers[i].ppGoals = ppGoals;
            myPlayers[i].shGoals = shGoals;
            myPlayers[i].gwGoals = gwGoals;
            myPlayers[i].otGoals = otGoals;
            myPlayers[i].shots = shots;
            myPlayers[i].shotPercent = shotPercent;
            strcpy(myPlayers[i].timeOnIce, timeOnIce);
            myPlayers[i].shiftsPerGame = shiftsPerGame;
            myPlayers[i].faceOffWinPercent = faceOffWinPercent;
            i++;
         }
            return 0;
}


int main(int argc, char *argv[])
{
  int numPlayers;
  char myStr[] = "nhl0708.txt";
  char myPlayers[1000];
  numPlayers = getNumPlayers(myStr);
  getLength(numPlayers, myStr);
  myPlayers = loadData(numPlayers, myStr);
  sortStats(numPlayers, myPlayers);
  system("PAUSE");
  return 0;
}

[Elysia]

You cannot return an array, but you can pass an array.
If both functions need it, define it is the most common scope you can find.
Since main calls both functions, have main define it and pass it along as arguments to both functions.
One can fill the struct, and one can use it.

Are you making a game, perchance?
Have you ever thought about C++? It is, after all, the preferred language for games.

Also, you have far too many globals. Globals are bad, because they can easily created bugs and make code a mess.
Move them inside main and pass them around as arguments whenever necessary.
At least, I think you should avoid globals for now.

[mikeman]

No, not making a game, not trying to at least, maybe it could be looked at in that light.

Have a class that was supposed to be about C++, started out spending the better part of 12 weeks learning Matlab, a couple on C, and maybe 3 lectures on C++. Have a project to find a "neat data set", and ask some "neat questions" and have the program compute the answers. Can be in C or C++, but since we've had maybe 4 hours spent on C++, I don't know enough about the difference between C and C++ to really be able to write anything useful using that...and apparently I don't know a whole lot about C either, or just haven't practiced enough...either way...

[mikeman]

I know globals aren't the best idea, but I didn't think it would have been a problem for this program. Removed them anyhow, and just defined them in each function they were being called in.

[Elysia]

Well, that's completely alright. It's not a huge deal. You can learn other languages at a later date, if you wish.
I wish just thinking if you wanted to write a game, then C++ might be better since most games are written in C++.
It's best to prioritize one language first! Since you've already started with C, you might as well continue, until you have an idea of what you want to do.

[mikeman]

You cannot return an array, but you can pass an array.
If both functions need it, define it is the most common scope you can find.
Since main calls both functions, have main define it and pass it along as arguments to both functions.
One can fill the struct, and one can use it.

Back to this...

We didn't spend much time on using define. And looking a source I've been trying to use as reference, I see there's a way to define structures using something like this

  typedef struct {
          char name[25];
          char team[5];
          int goals;
          int assists;
          .
          .
          .
  } myPlayers;

Is this what you're referring to me doing in main? And would that be setup correctly like that if that is indeed what you're referring to?

[Elysia]

Put that struct outside main (typically in a header), first.

int main()
{
    Player player[n];
    Function1(player, sizeof(player), ...);
    Function2(player, sizeof(player), ...);
}

And remember that the typedef "renames" the struct, from anonymous to myPlayers. It does not create an instance of it, so you probably want to name it Player or something.

Now that you are passing player to the functions, they can do the work on them, and the work carries on as you pass it to the next function.