Please elaborate on each of the comments written in the code. I don't really understand the:

Runnable r = new Increase(c, 3);

Thread t = new Thread(r);

t.start();

I don't understand why sometimes it prints 0 and other times 3. I really don't understand this comment:

/*

toString() method is called while print the object and but it may print 0,

since main() thread may ends before thread t. Note that sometimes it may print 3 also.

*/

What does this mean "since main() thread may ends before thread t" ?

Thank you for the help!

Counter class:

public class Counter { private int count; public Counter() { count = 0; }

public void increment() { count++; }

public int getCount(){return count;} }

package ch04.threads;

public class Increase implements Runnable { private Counter c; private int amount; public Increase (Counter c, int amount) { this.c = c; this.amount = amount; } public void run() { for (int i = 1; i