Dynamic Size of Class

Question

Hi again. I really don't know why this happens and i need your help here. I have this class:
static public class Data{
        static String subfolder = "";
        static String[] citation = new String[2000];
        static String[] reference = new String[2000];
    }And i create a new variable for this class like this:
Data[] SubFolder = new Data[2000]; Because i need to have, the class organized like this:
SubFolder[0].subfolder = Year0;
SubFolder[0].citation[0] = CITATION1;
SubFolder[0].reference[0] = REFERENCE1;
SubFolder[0].citation[1] = CITATION2;
SubFolder[0].reference[1] = REFERENCE2;
SubFolder[0].citation[2] = CITATION3;
SubFolder[0].reference[2] = REFERENCE3;
SubFolder[1].subfolder = Year1;
SubFolder[1].citation[0] = CITATION1;
SubFolder[1].reference[0] = REFERENCE1;
SubFolder[1].citation[1] = CITATION2;
SubFolder[1].reference[1] = REFERENCE2;
....now, the strange is, when i test the following code:
SubFolder[0].subfolder = "test";
SubFolder[1].subfolder = "test1";
System.out.println(" Position 0 = " + SubFolder[0].subfolder);
System.out.println(" Position 1 = " + SubFolder[1].subfolder);and i print out to console the result is the same! The result is:
Position 0 = test1
Position 1 = test1what i'm doing wrong?? Thanks for your help!

Answer 1

static String subfolder = "";
static in this context means there is only one subfolder value, no matter how many Data objects you create. It belongs to the Data class, not to each instance.
SubFolder[0].subfolder = "test";
SubFolder[1].subfolder = "test1";So the above lines are actually equivalent to:
Data.subfolder = "test";
Data.subfolder = "test1";