Insert Selected Objects into Array

Question

I’m doing a Formula 1 racing program, my program performs reading of various race files, and creates the objects of the race. I need to deploy in this program a class that has an array to store only Pilots who have points above 0, and if the pilot is already in the array, their score should be updated, however, the objects are not being created in the array:

Part of the Main Class:

public class Controle {
    public static void main(String[] args) {

        Temporada2013 temporada = new Temporada2013();
        File arquivos[];
        File diretorio = new File("/Users/leonardobruksch/NetBeansProjects/Corridas");
        arquivos = diretorio.listFiles();

        for(int a=0;a<arquivos.length;a++){
            Provas prova = new Provas();
        try {
            FileReader fr = new FileReader(arquivos[a]);
            BufferedReader in = new BufferedReader(fr);
            String line = in.readLine();
            line = in.readLine();
            while (line != null) {
                String result[] = line.split(";");
                int x = Integer.parseInt(result[6]);
                prova.inserePiloto(result[0], result[1], result[2], result[3], result[4], result[5], x);
                if(x > 0)
                    temporada.inserePilotosPontuados(result[1], result[2], x);
                line = in.readLine();
            }

Part of the class Temporada2013 that performs the insertion:

public class Temporada2013 {

    Piloto[] pontuados = new Piloto[30];

    public void inserePilotosPontuados(String driver, String team, int points) {
        for(int i=0;i<getLast();i++){
            if(pontuados[i].getDriver().equalsIgnoreCase(driver)){
                pontuados[i].setPoints(pontuados[i].getPoints()+points);
                return;
            }

        }
        pontuados[getLast()] = new Piloto(driver, team, points);
    }

    private int getLast(){
        int last = 0;
        for(int i=0;i<pontuados.length;i++){
            if(pontuados[i] == null)
                last = i;
                return last;
        }
        return last;
    }

What is occurring is that the above method, after it is executed and displayed, is creating only one object in the array, rather than creating several.

Answer 1

I believe the problem is here:

private int getLast(){
    int last = 0;
    for(int i=0;i<pontuados.length;i++){
        if(pontuados[i] == null)
            last = i;
            return last;
    }
    return last;
}

As you can see, the if did not have keys {}. Keys are used to delimit blocks of code. Omitting keys, you make only the instruction after the if be part of it.

In short... by removing the keys, you remove the ability of your if to have several instructions.

Explaining with the code is easier. See the snippet of your code below:

int last = 0;

for(int i=0;i<getLast();i++){
    if(pontuados[i] == null)
        last = i;
        return last;
}

To do that would be the same as to do:

int last = 0;

for(int i=0;i<getLast();i++){
    if(pontuados[i] == null) {
        last = i;
    }

    return last;
}

Thus the for above will return last in the first iteration. How last = 0, your method will return 0 at all times. Return 0 will cause a side effect on the method inserePilotosPontuados, where:

pontuados[getLast()] = new Piloto(driver, team, points);

It’s the same as doing:

pontuados[0] = new Piloto(driver, team, points);

The code below should work smoothly:

private int getLast() {
    int last = 0;

    for (int i = 0; i < pontuados.length; i++) {
        if (pontuados[i] == null) {
            last = i;
            return last;
        }
    }

    return last;
}