This document discusses Java key concepts like comments, examples of Java code, reserved words, modifiers, and classes. It contains code examples to demonstrate single-line and multi-line comments. It also lists Java reserved words, modifiers like public and private, and defines a class as a blueprint for objects.

1. Java key definition & practice
java programming
Nooria Esmaelzade
2016

2. Comments
// this is a single comment
/*this is a block comment
* it can be more than one line
*/
/** this is a javadoc comment
*It is used to display the longer comment
*We can generate a html page by using javadoc command in CMD
*/

3. Examples
/* UnicodeCommentDemo.java
* Java programs are written using Unicode characters
* Unicode presenting a character recognized as usual Java token
*/
public class ClassBExcersise
{
public static void main(String[] args)
{
// The method will print hello java in console
System.out.println(“hello java”);
}
}
Paragraph comment example
Single line comment example

4. Reserved words
abstract
assert
boolean
break
byte
case
catch
char
class
const
continue
default
do
double
else
enum
extends
false
final
finally
float
for
goto
if
implements
import
instanceof
int
interface
long
native
new
null
package
private
protected
public
return
short
static
strictfp
super
switch
synchronized
this
throw
throws
transient
true
try
void
volatile
while

5. Modifiers
Public
Private
Protected
Final
Abstract
static

6. Class
A blue print for the objects

7. Show message in a box