Clueless - Method to get Object

Question

First of all I'd like to thank everyone in advance for any help. I am completely new to Java, and am making my first attempt at a program for an assessed project.
The following code is something I am having trouble with:
public class Train {
     public static void trainArr ()
        Timetable train1 = new Timetable ();
        train1.depart = 12.00;
        train1.arrive = 13.00;
        train1.journey = (train1.arrive - train1.depart) * 100;
        Object[] timeTable;
        timeTable = new Object[6];
        timeTable[0] = train1;
        System.out.println(timeTable[0]);
}My aim here is to have the Train Object contain the elements 'depart' 'arrive' and 'journey' each of which is a time. There will be a total of 6 Train Objects stored in an array. What I don't know how to do is separate the individual elements of the Object after they have been stored in the array - so that they can be changed by user input, sorted, etc. I have been told that I have to do so using a Method call such as trainArray[0].getDepartalthough I don't really understand how to construct this Method. I know this may be a very broad question, but it is hard to define something I don't fully understand. I would very much appreciate being pointed in the right direction or given an example to follow. If any more information is needed let me know.
Thanks again!

Answer 1

What version of the SDK are you using? The Calendar class has been around for as long as I've been using Java (not long, admittedly, but still...). Also, I'd be careful about using doubles to represent time - how would you handle a double of 12.87? Using appropriate long values to represent time will help your program be more extensible - we can work on getting Calendar to work if you would like, but no pressure... :o)
Now, onto your question...
In your code, you are trying to construct a Train object using just a string (new train("Train1")), when your constructor code asks for a Train object and two double primitives (public Train(Train trainID, double departure, double arrival)). I think what you're shooting for is that trainID is a String, rather than a whole Train, so you'll need to modify your code as follows:
class Train {
    // These variables are specific to each Train object
    String trainID; // String, not Train...
    double departure;
    double arrival;
    double duration;
    // Construct a Train object using a String id,
    // departure, and arrival times)
    public Train(String trainID, double departure, double arrival) {
        this.trainID = trainID;
        this.departure = departure;
        this.arrival = arrival;
        duration = arrival - departure;
    public double getDuration() {
        return duration;
    public static void main(String[] args) {
        // Create an array of Trains
        Train[] schedule = new Train[6];
        // Initialize some variables to be used
        // to construct a Train
        String trainID = "Train1";
        double departure = (12.00);
        double arrival = (12.30);
        // Create a new Train and add it to the array
        schedule[0] = new Train (trainID, departure, arrival);
        // Print the duration of the first train trip
        // in the array
        System.out.println(schedule[0].getDuration());
}P.S. It's really no bother. We're here to help. :o)