Implementing Runnable and extending thread - multithreading

Question

I have been given the task of running two threads one using extends and one using implements runnable, the output is meant to be similair to this
F(0)
F(1)
F(2)
.........
S(0)
S(1)
S(2)
So far im getting
F(0)
S(1)
F(1)
F(2)
S(2)
public class Fast implements Runnable
{
/** Creates a new instance of Fast */
public void run()
{
for(int i = 0; i <= 9; i++)
{
try
{
System.out.println("F("+ i + ")");
Thread.sleep(200);
}
catch(InterruptedException e)
{
String errMessage = e.getMessage();
System.out.println("Error" + errMessage);
}
}
}
}
and
public class Slow extends Thread
{
/** Creates a new instance of Slow */
public void run()
{
for(int i = 0; i <= 6; i++)
{
try
{
System.out.println("S("+ i + ")");
Thread.sleep(400);
}
catch(InterruptedException e)
{
String errMessage = e.getMessage();
System.out.println("Error" + errMessage);
}
}
}
}
With the main
public class Main
{
public static void main(String args[])
{
Fast f = new Fast();
Slow s = new Slow();
Thread ft = new Thread(f);
ft.start();
s.start();
}
}

Answer 1

It seems like you want to get Slow to run after Fast? Your output is pretty much what i would expect. Eventually F will finish faster (just 2000ms) and S will still be running (2800ms). I'm not what this assignment has got to do with implementing Runnable or extending Thread since they give you the same end-result.
If you want F to finish completely before S you need to join on F first, like this:
Fast f = new Fast();
Slow s = new Slow();
Thread ft = new Thread(f);
ft.start();
ft.join();
s.start();
That will wait for ft to complete before even starting S giving you the desired output F1, F2,... S1,S2,...