AAAGGGHH!!! Selection sort with external file!

Question

Hi, i am trying to sort marks from an external file in ascending order, using a selection sort via an existing class StudentMark.
However, i am receiving 1 error when i compile it!!!!
code below:
import java.io.*;
import java.util.*;
class sort
     // method to display the contents of an array
     static StudentMark data[];
     static void displayData(int[] data)
          try
               data = StudentMark.loadMarks();
               for (int index=0; index != data.length; index++)
                    System.out.println(data[index]+"\t");
          catch(Exception e)
               System.out.println(e.getMessage());
     static int positionOfLargest(int[] data, int limit)
     // method to return the position of the largest item
     // in the data with bounds 0..limit
          int largest = data[0];
          int indexOfLargest = 0;
          for (int index=1; index <= limit; index++)
               if (data[index]> largest)
                    largest = data[index];
                    indexOfLargest = index;
          return indexOfLargest;
     public static void selectionSort(int[] data)
     // method to sort the contents of an data into ascending order
          int temporary;
          int position;
          int size=data.length;
          for (int index=size-1; index > 0; index--)
               position=positionOfLargest(data, index);
               // swap numbers
               if (index != position)
                    temporary = data[index];
                    data[index] = data[position];
                    data[position] = temporary;
     public static void main(String[] args)
          int[] data;
          System.out.println("numbers before being sorted\n");
          displayData(data);
          selectionSort(data);
          System.out.println("numbers after being sorted\n");
          displayData(data);
the error is: sort.java:14: incompatible types -                data = StudentMark.loadMarks();
^
Can anyone see what i am doing wrong??
Thanks!!

Answer 1

static StudentMark data[];
data = StudentMark.loadMarks();the error message "incompatible types" means that the type of data and the return type of StudenMark.loadMarks() are not compatible.
in case of we don't know the return type of StudentMark.loadMarks() i could only guess:
class StudentMark {
  public static StudentMark[] loadMarks() {
}if you used that kind of method declaration you should change your declatation of the variable data:
public static StudentMark[] data;then your codeline 14 shouldn't be a problem any longer.
StudentMark[] data and StudentMark data[] ARE different!
hope it helps.