JAVA SYNTAX CHEAT SHEET

BASIC DEFINITIONS
Class Describes a particular kind of object. It can contain related methods and variables.
Method A function defined in a class. Methods implement the behavior for objects.
Object The principal building blocks of Java. Objects consist of variables (data) and methods (functionality).
COMMENTS
HTML Comments
<!-- comment --> Sent to the client in the viewable page source.
JSP Commens (Not Sent to Client)
<%-- comment --%> Comments in JSP file.
// comment Comment in scriplet part of JSP file.
ELEMENTS
Declaration
<%! declaration %> Creates a global variable or method.
Expression
<%= expression %> Statements evaluated on the server before the page is outputted to the client.
Page Directive
<%@ directive %> Attributes that apply to the entire page.
Scriplet
<% code fragment of one or more lines %> Contains a block of scripting code which is executed when the page is generated.
Taglib Directive
<%@ taglib uri="URIToTagLibrary" prefix="tagPrefix" %> Defines a tag library and prefix for tags used in a JSP page.
SEPARATORS
( ) Used to surround parameters
{ } Defines a block of code for a class or method or to contain the values of automatically initialized arrays
[ ] Declares arrays or references array values
; Denotes the end of a statement
, Separates variables
. Separates package names from subpackages/ classes or a variable/method from a reference variable
PRIMITIVE DATA TYPES
Type Description Bits
(Integers)
byte Byte-length integer 8
short Short integer 16
int Integer 32
long Long integer 64
(Real Numbers)
float Single-precision floating point 32
double Double-precision floating point 64
(Other)
char A single character 16
boolean A boolean value (true or false) 1
OPERATORS
+ addition of numbers, concatenation of Strings
+= add and assign numbers, concatenate and assign Strings
- subtraction
-= subtract and assign
* multiplication
*= multiply and assign
/ division
/= divide and assign
% take remainder
%= take remainder and assign
++ increment by one
-- decrement by one
> greater than
>= greater than or equal to
< less than
<= less than or equal to
! boolean NOT
!= not equal to
&& boolean AND
|| boolean OR
== boolean equals
= assignment
STATEMENTS
IF/Else
if (statement) {
code_block_true;
} else {
code_block_false;
}
While
while (condition)
{
code_block;
}

Control Flow


Selection

If
Else
Switch
Case

Loop

While
Do
For

Exception

Throw
Try
Catch
Finally

Branch

Return
Break
Continue
Label

Key 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