本文實(shí)例講述了PHP面向?qū)ο蟪绦蛟O(shè)計(jì)之命名空間與自動加載類。分享給大家供大家參考，具體如下：
命名空間
避免類名重復(fù),而產(chǎn)生錯誤。
<?phprequire_once "useful/Outputter.php";class Outputter { // output data private $name; public function setName($name) { $this->name = $name; } public function getName() { return $this->name; }}$obj = new Outputter(); // 同一命名空間下,類名不能相同,默認(rèn)命名空間為空。空也是一種命名空間。$obj -> setName("Jack");print $obj->getName();//namespace useful; // 更改命名空間，否則查詢不到Hello類,Fatal error: Class 'my/Hello' not found$hello = new Hello();?><?php// useful/Outputter.phpnamespace useful; // 命名空間class Outputter { //}class Hello {}?>如何調(diào)用命名空間中的類
<?phpnamespace com/getinstance/util;class Debug { static function helloWorld() { print "hello from Debug/n"; }}namespace main;// com/getinstance/util/Debug::helloWorld(); // 找不到Debug類/com/getinstance/util/Debug::helloWorld(); // 加斜杠之后，就從根部去尋找了。// outPut:hello from Debug?>使用use關(guān)鍵字
<?phpnamespace com/getinstance/util;class Debug { static function helloWorld() { print "hello from Debug/n"; }}namespace main;use com/getinstance/util;//Debug::helloWorld(); //Fatal error: Class 'main/Debug' not foundutil/Debug::helloWorld();?>使用下面的處理，直接可以調(diào)用類
<?phpnamespace com/getinstance/util;class Debug { static function helloWorld() { print "hello from Debug/n"; }}namespace main;use com/getinstance/util/Debug; // 直接使用到類Debug::helloWorld();?>/表示全局
global.php
<?php// no namespaceclass Lister { public static function helloWorld() { print "hello from global/n"; }}?><?phpnamespace com/getinstance/util;require_once 'global.php';class Lister { public static function helloWorld() { print "hello from ".__NAMESPACE__."/n"; // __NAMESPACE__當(dāng)前namespace }}Lister::helloWorld(); // access local/Lister::helloWorld(); // access global?>輸出：
hello from com/getinstance/util
hello from global
命名空間加{}
<?phpnamespace com/getinstance/util { class Debug { static function helloWorld() { print "hello from Debug/n"; } }}namespace main { /com/getinstance/util/Debug::helloWorld();}?>output:
hello from Debug
全局命名空間
<?phpnamespace { // 全局空間 class Lister { public static function helloWorld() { print "hello from global/n"; } }}namespace com/getinstance/util { class Lister { public static function helloWorld() { print "hello from ".__NAMESPACE__."/n"; } } Lister::helloWorld(); // access local /Lister::helloWorld(); // access global}?>__autoload 自動加載類
ShopProduct.php
<?phpclass ShopProduct { function __construct() { print "ShopProduct constructor/n"; }}?><?phpfunction __autoload( $classname ) { // 自動加載，根據(jù)類名加載類 include_once( "$classname.php" );}$product = new ShopProduct( 'The Darkening', 'Harry', 'Hunter', 12.99 );?>output:
ShopProduct constructor
進(jìn)一步優(yōu)化處理
位于文件夾business/ShopProduct.php
<?phpclass business_ShopProduct { // 這里的類命名就要遵循規(guī)則了 function __construct() { print "business_ShopProduct constructor/n"; }}?><?phpfunction __autoload( $classname ) { $path = str_replace('_', DIRECTORY_SEPARATOR, $classname ); // 智能化處理 require_once( "$path.php" );}$x = new ShopProduct();$y = new business_ShopProduct();?>output:
ShopProduct constructor
business_ShopProduct constructor
希望本文所述對大家PHP程序設(shè)計(jì)有所幫助。
新聞熱點(diǎn)
疑難解答
圖片精選
