http://www.javacoffeebreak.com/articles/toptenerrors.html

definitions:
class: defines the variables and methods of an object
object: instance of a class

instance variable:	class Foo { int a; }
	access with:		f = Foo(); f.a = 0
class variable:		class Foo ( static int a; }
	access with		Foo.a = 0

instance method		class Foo { void a { ; } }
	call with:		f = Foo(); f.a();
class method		class Foo { static void a { ; } }
	call with:		Foo.a();
instance: each instance of an object has its  own variable/method.
class: variable/method exists only once.
!! static variables can only be accessed from static methods and vice versa.


private: method / variable can only be accessed within class
public: necessary for main() and toString(). necessary for extending other public methods.


declaring array:	int foo[] = new int[10];

abstract:
abstract public class Foo1 { abstract void Bar(); }

public class Foo2 extends Foo1 { void Bar() { ; } }


interface: 
like abstract but without normal methods or variables, only abstract methods and contsants.
interface class Foo1 { void Bar(); }

public class Foo2 implements Foo1 { void Bar() { ; } }



this, super: this references to an object itself. super references a parent method/variable.
public class Foo1 { abstract void Bar() { ; } }

public class Foo2 extends Foo1 { void Bar() { super.Bar(); } }


constructors are never inherited!
call to super. in a constructor must be first statement (because otherwise the default constructor is called)