Thread: Help with parallel array

/*
Program created by: Craig Noguez
	A program that creates a file containing a table showing the student ID numbers and averages of
	all the students in a course in ascending order by ID number.
*/
 
import java.io.*;
import java.util.Scanner;
 
public class assignment6
{
	public static void main(String[] args) throws IOException
	{
		Scanner keyboard = new Scanner(System.in);
		String fileName = "";
		String[] idnumbers;
		String[] array;
		String[] average;
		int index = 0;
		String[] test = new String[100];
 
		System.out.println("Enter the name of the file you would like to read.");
		fileName = keyboard.nextLine();
 
		System.out.println();
 
		idnumbers = getid(fileName);
		average = getavg(fileName);			
		selectionSort(idnumbers);
		System.out.println("Enter the name of the file you would like to save the data to.");
		fileName = keyboard.nextLine();
 
		PrintWriter outputFile = new PrintWriter(fileName);
		outputFile.printf(" IdNumber						Average\n");
		for(index = 0; index < average.length; index++)
			if(average[index] == null)
				outputFile.close();
			else
				outputFile.printf("%5s %23s\n", idnumbers[index], average[index]);
	}
 
	/**
		A method to get the id-number from a text file.
 
		@param fileName  The file to get the id-numbers from
		@return idnumbers  Returns the array with the idnumbers stored
	*/
 
	public static String[] getid(String fileName) throws IOException
	{
		File file = new File(fileName);
		Scanner inputFile = new Scanner(file);
		int index = 0;
		int startid = 2;
		String[] idnumbers = new String[100];
		String[] WholeFile = new String[100];
 
		while(inputFile.hasNext() && index < idnumbers.length)
		{
			WholeFile[index] = inputFile.nextLine();
			index++;
		}
 
		for(index = 0; startid < WholeFile.length; index++)
		{
			idnumbers[index] = WholeFile[startid];
			startid += 4;
		}
		return idnumbers;
	}
 
	/**
		A method to get the averages from a text file.
 
		@param fileName The file to get the averages from
		@return average  Returns an array with the averages stored in it
	*/
 
	public static String[] getavg(String fileName) throws IOException
	{
		File file = new File(fileName);
		Scanner inputFile = new Scanner(file);
		int index = 0;
		int startavg = 3;
		String[] WholeFile = new String[100];
		String[] average = new String[100];
 
		while(inputFile.hasNext() && index < average.length)
		{
			WholeFile[index] = inputFile.nextLine();
			index++;
		}
 
		for(index = 0; startavg < WholeFile.length; index++)
		{
			average[index] = WholeFile[startavg];
			startavg += 4;
		}
		return average;
	}
 
	/**
		A method that sorts the inputed string into alphabetical order.
 
		@param array  The string to be sorted.
	*/
	public static void selectionSort(String[] array)
	{
		int startScan, index, minIndex;
		String minValue;
 
		for (startScan = 0; startScan < (array.length-1); startScan++)
		{
			minIndex = startScan;
			minValue = array[startScan];
			for(index = startScan + 1; index < array.length; index++)
			{
				if (array[index] == null)
					break;
				else if (array[index].compareTo(minValue) < 0)
				{
					minValue = array[index];
					minIndex = index;
				}
			}
			array[minIndex] = array[startScan];
			array[startScan] = minValue;
		}
	}
}

I need my id number to get sorted along with the average but I have no idea how to do it and my teacher barely touched on parallel arrays help please thanks!

Ya see thats easy ive looked at it and it would make life so much simpler but my teacher is a nazi and she wont let us use it