Session 9

We started class by looking at HW#1 and talking about what I expected for full credit.

We continued by looking at HW#2 and talking about some of the details of both the assignment and assignments in general (using the homework submission system).

Memory

public class MemoryDemo
{
	public static void main(String[] args)
	{
		int x;
		int y;
		x=5;
		y=x;
		y++;
		System.out.println("x="+x);
		System.out.println("y="+y);

		WesternTown town1;
		WesternTown town2;
		town1 = new WesternTown();
		town2 = town1;
		town2.increaseTrouble();
		System.out.println("town1="+town1.troubleCount());
		System.out.println("town2="+town2.troubleCount());
	}
}

(You will need a version of WesternTown.java to run this)

What do you think will happen?

Why?

Now, what if I add in:

String a="Hello";
String b=a;
b="Goodbye";
System.out.println(a);
System.out.println(b);

Discussion Points

• Strings are immutable - thus why b no longer equals a.
• Strings, while objects (with methods and instance variables) have SOME behavior of primitive data types (you can create one without using a constructor.