class problem

[McChill]

I'm not sure which method is messed up, but I think it is either switchLines(...) or randomizeList()

Whenever I run the program it displays the list at first correctly. Then the two println's"The lines have been.....". But whenever it displays the list after being randomized I get mized results. Sometimes the list will not have changed (or changed back to the same?), sometimes there will be multiples of the same line like this for example --
This is the second line
This is the second line
This is the first line
This is the fourth line

package test;
import java.util.HashMap;
import java.util.Random;
import java.io.*;

public class Test {
	
	private HashMap<Integer, String> theLines = new HashMap<Integer, String>();
	private String theList[];
	private Random random;
	
	
	public Test() {}
	
	/**
	 * Set the lines into a hashmap
	 */
	public void setLines()
	{
		theLines = new HashMap<Integer, String>();
		theLines.put(0, "This is the first line");
		theLines.put(1, "This is the second line");
		theLines.put(2, "This is the third line.");
		theLines.put(3, "This is the fourth line.");
	}
	
	/**
	 * Set the lines into an array
	 */
	public void setList()
	{
		theList = new String[4];
		for(int x = 0; x < 4; x++)
			theList[x] = theLines.get(x);
		
	}
	

	public String[] getList()
	{
		return theList;
	}
	
	/**
	 * A function to switch two lines.
	 * @param line1 The line to be switched
	 * @param line2 The line to switch it with
	 */
	public void switchLines(int line1, int line2)
	{
		String middleMan = "";
		middleMan = theLines.get(line1);
		theList[line1] = theLines.get(line2);
		theList[line2] = middleMan;
	}
	
	/**
	 * The function to randomize the lines. 
	 * loop it a random number of times
	 * when a and b are not equal, switch the lines
	 */
	public void randomizeList()
	{
		random = new Random();
		int x = random.nextInt();
		while(x == 0)
			x = random.nextInt();
		for(int t=0;t < random.nextInt();t++) {
			int a = random.nextInt(4);
			int b = random.nextInt(4);
			while(a == b) {
				a = random.nextInt(4);
				b = random.nextInt(4);
			}
			switchLines(a, b);
		}
	}
	
	//Displays the list
	public void displayTheList()
	{
		for(int x = 0;x < 4;x++)
			System.out.println(theList[x] + "\n");
	}
	
	
	
	
	
	public static void main(String args[]) {
		Test t = new Test();
		String temp = "";
		t.setLines();		
		t.setList();		
		t.displayTheList();
		t.randomizeList();
		System.out.println("The lines have been randomized.\n");
		System.out.println("It is up to you to put them back in order.\n");
		t.displayTheList();
		System.out.println("Type in switch to change the order");
		BufferedReader dataIn = new BufferedReader(new InputStreamReader(System.in));
		try{
			temp = dataIn.readLine();
			if(temp.equals("switch"))
			{
				System.out.println("Okay, what two lines should be switched?");
				String which = dataIn.readLine();

				//under construction...	
					
				System.out.println("\n\nThe new order is:\n");
				t.displayTheList();
						
			}
		}catch(IOException e) {
			System.out.println("Error in getting input.");
		}
				

	}

}

I know I'm missing code in the main, but my main focus right now is figuring out what it wrong with the randomizing.

[pbrockway2]

In your switchLines() method you swap two array entries. Or, at least you mean to.

public void switchLines(int line1, int line2)
{
    String middleMan = "";
    middleMan = theLines.get(line1);
    theList[line1] = theLines.get(line2);
    theList[line2] = middleMan;
}

Don't you mean theList[line2] rather than theLines(line2) in that middle assignment?

BTW - you don't really need to assign middleMan an empty String like that, you can just say:

    String middleMan = theLines.get(line1);