Java

I'm trying to take a java test today so here is a quick overview:
 Java features: simple, object-oriented, robust, multi-threaded, architecture-neutral, interpreted and high-performance, distributed and dynamic.
Code is written usually in one of two ways : viz. procedural  -  set of instructions that defines "what is happening" or second object-oriented  - code is organized around data to describe "who is being affected".

Common data types include byte, int, double etc. You can use instanceOf
String operations : StartsWith, equalsIgnoreCase, regionMatches, reverse etc.

Common data structures are Vector, Dictionary, Hashtable, StringTokenizer, BitSet, Observable,
use static and this keywords for class methods liberally eg:
 class Box
{
public static void main(string args[])

use implements and extends judiciously
class Deadlock implements Runnable 
class Box extends Shape

 use Thread, ThreadGroup and Runnable
 use Cloneable interface
 use Observable class and Observe interface. Observable calls notifyObservers() and Observer declares update(Observable, Object) method.