Language Fundamentals:
1. Date classes in two different pakages, java.util and java.sql...
2. identifier start with letter, $ or _.
3. primitives data type
boolean 1 bit
byte 8 bits
char 16 bits
short 16 bits
int 32 bits
float 32 bits
long 64 bits
double 64 bits
4. short s1= 9 + s(short) ----- ompile error coz 9 is int.
5.Arrays:
A java array is an ordered collection of primitives,object referneces, or other arrays.
6. variables and initialization
7. Argument passing
8 Garbage collection: cannot force garbage cellection. System.gc() or Runtime.gc() noy 100 percent.


Operators and Assignments:
1. The Unary Operators: ++ and --; + and -; ~ and !; cast()
2. Arithmetic Operators: * and /; %; + and -;
3. The Shift Operators: <<, >> and >>>
4. The Comparision Operators: <, <= , >, >=, == and !=...instanceof
5. The Bitwise Operators: &, ^ and / ==== AND , XOR and OR
6. The Short-Cricuit Operators: && ans ======AND and OR
7. The Assignment Operators

Modifiers: public,protected,private
final, abstract, static, native,transient,synchronized,voliatile
1. The Access modifiers: public; protected;private; default
legal overridden method access:
Private ->Default -> Protected ->Public

2.
final: -- classes, methods, and variables
A final class may not be subclassed.
A final variable may not be modified once it has been assigned a value.
A final method may not be overridden.
abstract: --classes and methods.
If a class constains one or more abtract methods, the compiler insists that the class must be declared abstract.
an abstract class must be subclassed.

static: -- methods, variables and even a strange kind of code that is not part of a method.
non-static(instance) methods --this otherwise error for "this"
A static method may not be overridden to be non-static.
native:

transient:
synchronized:
volatile: