NullPointerException

I'm trying to make a program. I'm using a while loop to keep asking for a name and when "done" is entered it exits the loop. It stores the names in an array and prints it out as you enter it. I cant get it to exit the loop.
This is the Source Code:

Code:

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import java.util.*;

public class TimeCard {

    public static void main(String sArgs[]){

                Scanner oScan = new Scanner(System.in);
                String[] aStudentNames = new String[150];
                final String[] sDone = {"done"};
                int iA = 0;
                while(aStudentNames[iA].compareToIgnoreCase(sDone[0]) > 0 || aStudentNames[iA].compareToIgnoreCase(sDone[0]) < 0){
                        System.out.println("What is your name?");

                        aStudentNames[iA] = oScan.nextLine();

                        System.out.println(aStudentNames[iA]);
            ++iA;
                }





    }


}

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Code:

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while(aStudentNames[iA].compareToIgnoreCase(sDone[0]) > 0 || aStudentNames[iA].compareToIgnoreCase(sDone[0]) < 0)

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its shorter to write

Code:

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while(!aStudentNames[iA].equalsIgnoreCase("done"))

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(an array with only one string makes no sense in my opinion)
So your problem is, that you access aStudentNames[iA] before you store the name on that array position. use maybe a do-while-loop instead of a normal while-loop.
Maybe:

Code:

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                Scanner oScan = new Scanner(System.in);
                String[] aStudentNames = new String[150];
                int iA = 0;
                do {
                        System.out.println("What is your name?");
                        aStudentNames[iA] = oScan.nextLine();
                        System.out.println(aStudentNames[iA]);
                } while (!aStudentNames[iA++].equalsIgnoreCase("done"));

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but you store "done" in your array too, dont know if you really want this :)

Code:

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                Scanner oScan = new Scanner(System.in);
                String[] aStudentNames = new String[150];
                int iA = 0;
                while(iA<149){
                        System.out.println("What is your name?");
                        String s =  oScan.nextLine();
                        if("done".equalsIgnoreCase(s)){
                                break;
                        }
                        aStudentNames[iA] =s;
                        System.out.println(aStudentNames[iA++]);
                }

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Thanks I'll try that!

It worked. Thanks a lot!