Writing into an array

Question

I have a method that needs to get years from an object and write that into an array. This is what I have so far:

    public int[] getYears() {   

    int[] years = null;

    for (RainfallYear rainfall : rainfallYears) {
        int year = rainfall.getYear();
        //insert year into int[] years array and return.
    }

    return years;
}

-

RainfallYear is an object that takes in a year and the values for rainfall during the months of the year:

public RainfallYear(int year, double[] rainfallMonths) {
    super();
    this.year = year;
    this.rainfallMonths = rainfallMonths;
}

This is how it would look like visually:

1914,50.9,87,115.8,32.3,47.1,56.6,97.1,63.9,48.1,62.4,110.3,190.8

rainfallYears is the name of an array of RainfallYear objects:

private RainfallYear[] rainfallYears = null;

I am struggling to insert the "extracted" year into an array to achieve the functionality of the int[] getYears method - to return an array of years.

---

Here is my previous attempt at doing this, but I don't think what I did was correct:

List<Integer> yearsList = null;
    for (int i = 0; i < rainfallYears.length; i++) {
        yearsList = new ArrayList<Integer>();
        yearsList.add(new RainfallYear(i, null).getYear());
    }

    int[] yearsArray = new int[yearsList.size()];
    for (int i = 0; i < yearsList.size(); i++) {
        yearsArray[i] = yearsList.get(i);
    }

    return yearsArray;

Answer 1

You are reinitializing your yearsList every iteration of the loop which will give it new data each time.

List<Integer> yearsList = null;
for (int i = 0; i < rainfallYears.length; i++) {
    yearsList = new ArrayList<Integer>();
    yearsList.add(new RainfallYear(i, null).getYear());
}

Instead, initialize your list outside of the loop like you did for your array.

List<Integer> yearsList = new ArrayList<Integer>();
for (int i = 0; i < rainfallYears.length; i++) {           
    yearsList.add(new RainfallYear(i, null).getYear());
}