Recitation 1: Intro java

Part 0: Eclipse and Java setup
- Go to www.eclipse.org/downloads and download "Eclipse IDE for Java Developers"
- Go to http://www.oracle.com/technetwork/java/javase/downloads/index.html
  and download "Java Platform (JDK) 7u2"
- Install Java
- Unzip Eclipse
- Set-up java for command line user (optional)
	• Windows (vista/7)
		> control panel -> system -> advanced system settings
		> select the "Advanced" tab
		> click on the button at the bottom called "Environment Variables..."
		> under "System Variables" click "New..."
		> name the variable "JAVA_HOME" and set the value to the absolute path
		  where java in installed
		> click ok
		> under "System Variables" look for a variable named "Path" if it does
		  not exist make create it.
		> edit the value in the path variable.  BE SURE NOT TO CHANGE WHAT IS
		  ALREADY THERE. At the very end of the current value add ";%JAVA_HOME%\bin"
		  (no quotes)
		> click ok
		> click ok again to exit the Environment Variables window
		> click ok again to exit the System Properties
		> Open a command prompt
		> enter "java -version" (no quotes)
		> you should see the version of java that has been installed.	
	• Mac/linux
		> using the editor of your choice edit your .bashrc file
		> append the following to your .bashrc file
		
		export JAVA_HOME=/path/to/java
		export PATH=$PATH:$JAVA_HOME/bin
		
		> make sure to replace /path/to/java with the actual path to java.
		> open terminal
		> type "java -version" (no quotes)
		> you should see the veresion of java that has been installed
	
Part 1: From c to java
- primitives
	• java does not have unsigned numbers
	• strings vs char*
		> strings are objects not just an array of chars
- No pointer arithmetic
	• no memory management - garbage collector
- array basics
	• array of 3 integers
		> int[] arr = new int[3]

Part 2: java keywords
- new
	• used to create objects
- public
	• visible to everyone
- private
	• visible to no one
- protected
	• visible to package and is inherited (to be discussed later)
- class
	• defines a class
	• classes can be public or private
- static
	• shared across objects
	• static methods can be called without an object
	• related to a class rather than an object

Part 3: code
- Hello world example
    • the main method
        > public static void main(string[] args)
    • basic system io
        > System.out.println
    • string manipulation
        > what is "5" + 2
        > what is 2 + "3"
		
- Basic Interface and substitutivity example
	• constructors