CSC152 2005S, Class 9: Numeric Values in Java

Admin:
* Reading: How to build your own classes (ready later this afternoon, I hope)
* Instructions on submitting labs to be released soon (I hope)
* Today's lab is a little bit more basic, but I think it needs to be.

Overview:
* Wrapup on strings
* Primitive types vs. classes
* Other Questions on numbers?
* Lab
* Reflection 

Interesting Java design: N ways to represent most numeric values
* Are numbers objects or something else?
  * Numbers can be represented in their base/primitive form
    byte,short,int,long: integers with different possible "sizes"
    float,double: approximations of real numbers
  * Numbers can also be represented as objects
    Byte,Short,Integer,Long
    Float,Double
  * "Arbitrary precision"
    java.math.BigInteger
    java.math.BigDecimal

Other questions on the reading?
* What's 1/3?
* You'll find out on the lab

Tips, Questions, and Such
* To refer to a method, we use either ObjectName.methodName or ClassName.methodName
* To refer to a field (particularly a constant field), we use either ObjectName.fieldName or ClassName.fieldName
  * E.g. java.lang.Integer.MAX_VALUE

Why is it that java.lang.Integer.MAX_VALUE != -1*java.lang.Integer.MIN_VALUE

Some of you have discovered

	import java.io.*

as a shorthand for

	import java.io.File;
	import java.io.FileReader;
	...

YOU MAY NOT DO SO

Why?

Suppose some writes
	import rebelsky.class1.*;
	import java.io.*;
	import schmitzc.coolstuff.*;

	...

	SillyThing st = new SillyThing();

So ... it's mostly to make it easier for the reader.  When you
are advanced programmers, it's okay.