Indice
grammatica
| Commenti |
| /* this is a multiline comment */
// this is a single-line comment
/** Javadoc comment */
|
| Letterali |
|
| number |
Type int |
| number[l | L] |
Type long |
| 0xhex |
Hex integer |
| 0Xhex |
Hex integer |
| 0octal |
Octal integer |
| [ number ].number |
Type double |
| number[ f | f] |
Type float |
| number[ d | D] |
Type double |
| [ + | - ] number |
Signed |
| numberenumber |
Exponent |
| numberEnumber |
Exponent |
| ‘character’ |
Single character |
| “characters” |
String |
| “” |
Empty string |
| \b |
Backspace |
| \t |
Tab |
| \n |
Line feed |
| \f |
Form feed |
| \r |
Carriage return |
| \” |
Double quote |
| \’ |
Single quote |
| \\ |
Backslash |
| \uNNNN |
Unicode escape (NNNN is hex) |
| true |
Boolean |
| false |
Boolean |
| Dichiarazione
di Variabili |
|
| [ byte | short | int |
long ] varname |
Integers |
| [ float | double ] varname |
Floats |
| char varname |
Characters |
| boolean varname |
Boolean |
| classname varname |
Class types |
| interfacename varname |
Interface types |
| type varname1,
varname2, varname3 |
Multiple variables |
Le
seguenti opzioni sono disponibili solo per
variabili
istanza e di classe |
|
| [ static ] variableDeclaration |
Class variable |
| [ final ] variableDeclaration |
Constants |
| [ public | private | protected
] variableDeclaration |
Access control |
| [volatile] varname |
Modified asynchro-nously |
| [transient] varname |
Not persistent |
| Assegnamento |
|
| variable = value |
Assignment |
| variable++ |
Postfix Increment |
| ++variable |
Prefix Increment |
| variable– – |
Postfix Decrement |
| – –variable |
Prefix Decrement |
| variable += value |
Add and assign |
| variable –= value |
Subtract and assign |
| variable *= value |
Multiply and assign |
| variable /= value |
Divide and assign |
| variable %= value |
Modulus and assign |
| variable &= value |
AND and assign |
| variable |= value |
OR and assign |
| variable ^= value |
XOR and assign |
| variable <<= value |
Left-shift and assign |
| variable >>= value |
Right-shift and assign |
| variable >>>= value |
Zero-fill right-shift and assign |
| Operatori |
|
| arg + arg |
Addition |
| arg – arg |
Subtraction |
| arg * arg |
Multiplication |
| arg / arg |
Division |
| arg % arg |
Modulus |
| arg < arg |
Less than |
| arg > arg |
Greater than |
| arg <= arg |
Less than or equal to |
| arg >= arg |
Greater than or equal to |
| arg = = arg |
Equal |
| arg != arg |
Not equal |
| arg && arg |
Logical AND |
| arg || arg |
Logical OR |
| ! arg |
Logical NOT |
| arg & arg |
AND |
| arg | arg |
OR |
| arg ^ arg |
XOR |
| arg << arg |
Left-shift |
| arg >> arg |
Right-shift |
| arg >>> arg |
Zero-fill right-shift |
| ~ arg |
Complement |
| (type)thing |
Casting |
| arg instanceof class |
Instance of |
| test ? trueOp : falseOp |
Tenary (if) operator |
| Oggetti |
|
| new class() |
Create new instance |
| new class(arg1, arg2, arg3, ...) |
New instance with parameters |
| object.variable |
Instance variable |
| object.classvar |
Class variable |
| object.method() |
Instance method (no args) |
| object.method(arg1, arg2, arg3, ...) |
Instance method |
| object.classmethod() |
Class method (no args) |
| object.classmethod(arg1 ,arg2 ,arg3,
...) |
Class method |
| Class.classmethod() |
Class method (no args) |
| Class.classmethod(arg1, arg2, arg3,
...) |
Class method |
| Array |
|
| type varname[] |
Array variable |
| type[] varname |
Array variable |
| new type[numElements] |
New array object |
| array[index] |
Element access |
| array.length |
Length of array |
| Cicli
e istruz. condizionali |
|
| if ( test) block |
Conditional |
if ( test ) block
else block |
Conditional with else |
switch (test) {
case value : statements
[break]
case value : statements
[break]
...
default : statement
} |
switch (only with integer or
char types) |
| for (initializer; test; change ) block |
for loop |
| while ( test ) block |
while loop |
do block
while (test) |
do loop |
| break [ label ] |
break from loop or switch |
| continue [ label ] |
continue loops |
| label: |
Labeled loops |
| Definizione
di Classi |
|
| class classname block |
Simple Class definition |
| [ final ] class classname block |
Class cannot be subclassed |
| [ abstract ] class classname block |
Class cannot be instantiated |
| [ public ] class classname block |
Class accessible outside package |
| class classname [ extends Superclass
] block |
Extends superclass |
| class classname [ implements interfaces
] block |
Implement one or more
interfaces |
| Metodi
e Costruttori |
|
| returnType methodName() block |
Basic method |
| returnType methodName(parameter, parameter,
...) block |
Method with parametersMethod with
parameters |
| [ abstract ] returnType methodName()
block |
Abstract method |
| [ static ] returnType methodName()
block |
Class method |
| [ native ] returnType methodName()
block |
Native method |
| [ final ] returnType methodName()
block |
Ifinal method |
| [ synchronized ] returnType methodName()
block |
Thread lock before executing |
| [ public | private | protected ] returnType
methodName() block |
Access control |
| super.methodName() |
Call a superclass’s method |
| classname() block |
basic constructor |
| classname(parameter, parameter, parameter...)
block |
constructor with parameters |
| [ public | private | protected] classname()
block |
Access control |
| this(...) |
Calls class’s constructor |
| super(...) |
Calls superclass’s constructor |
| Package
e Interfacce |
|
| import package.className |
Imports specific class name |
| import package.* |
Imports all public classes in package |
| package packagename |
Classes in this file belong
to this package |
| [ public ] interface interfaceName
block |
Simple Interface definition |
| interface interfaceName [ extends
anotherInterface ] block |
Extends interface |
| Eccezioni
e Controlli |
|
| synchronized ( object ) block |
Waits for lock on object |
try block
catch ( exception ) block
[ finally block ] |
Guarded statements
Executed if exception is thrown
Cleanup code |
try block
[ catch ( exception ) block ]
finally block |
Same as previous example (can use
optional catch or finally) |
Riferimenti
Bibliografici
-
"The Java ™ Language
Specification" disponibile
sul sito FTP di javasoft: ftp://ftp.javasoft.com/docs/specs
-
"Teach yourself
Java in 21 days" L. Lemay C.L. Perkins - SAMS.NET Publishing
(Edito in Italia da Apogeo)
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