了解类
class_exists验证类是否存在
<?php // TaskRunner.php $classname = "Task"; $path = "tasks/{$classname}.php"; if ( ! file_exists( $path ) ) { throw new Exception( "No such file as {$path}" ); //抛出异常,类文件不存在 } require_once( $path ); $qclassname = "tasks\\$classname"; if ( ! class_exists( $qclassname ) ) { throw new Exception( "No such class as $qclassname" ); //抛出异常,类不存在Fatal error: Uncaught exception 'Exception' with message 'No such class as tasks\Task' Stack trace: #0 {main} } $myObj = new $qclassname(); $myObj->doSpeak(); ?>
get_class 检查对象的类 instanceof 验证对象是否属于某个类
<?php class CdProduct {} function getProduct() { return new CdProduct( "Exile on Coldharbour Lane", "The", "Alabama 3", 10.99, 60.33 ); // 返回一个类对象 } $product = getProduct(); if ( get_class( $product ) == 'CdProduct' ) { print "\$product is a CdProduct object\n"; } ?> <?php class CdProduct {} function getProduct() { return new CdProduct( "Exile on Coldharbour Lane", "The", "Alabama 3", 10.99, 60.33 ); } $product = getProduct(); if ( $product instanceof CdProduct ) { print "\$product is a CdProduct object\n"; } ?>
get_class_methods 得到类中所有的方法列表,只获取public的方法,protected,private的方法获取不到。默认的就是public。
<?php class CdProduct { function construct() { } function getPlayLength() { } function getSummaryLine() { } function getProducerFirstName() { } function getProducerMainName() { } function setDiscount() { } function getDiscount() { } function getTitle() { } function getPrice() { } function getProducer() { } } print_r( get_class_methods( 'CdProduct' ) ); ?>
output:
Array ( [0] => construct [1] => getPlayLength [2] => getSummaryLine [3] => getProducerFirstName [4] => getProducerMainName [5] => setDiscount [6] => getDiscount [7] => getTitle [8] => getPrice [9] => getProducer )
更多验证
<?php class ShopProduct {} interface incidental {}; class CdProduct extends ShopProduct implements incidental { public $coverUrl; function construct() { } function getPlayLength() { } function getSummaryLine() { } function getProducerFirstName() { } function getProducerMainName() { } function setDiscount() { } function getDiscount() { } function getTitle() { return "title\n"; } function getPrice() { } function getProducer() { } } function getProduct() { return new CdProduct(); } $product = getProduct(); // acquire an object $method = "getTitle"; // define a method name print $product->$method(); // invoke the method if ( in_array( $method, get_class_methods( $product ) ) ) { print $product->$method(); // invoke the method } if ( is_callable( array( $product, $method) ) ) { print $product->$method(); // invoke the method } if ( method_exists( $product, $method ) ) { print $product->$method(); // invoke the method } print_r( get_class_vars( 'CdProduct' ) ); if ( is_subclass_of( $product, 'ShopProduct' ) ) { print "CdProduct is a subclass of ShopProduct\n"; } if ( is_subclass_of( $product, 'incidental' ) ) { print "CdProduct is a subclass of incidental\n"; } if ( in_array( 'incidental', class_implements( $product )) ) { print "CdProduct is an interface of incidental\n"; } ?>
output:
title title title title Array ( [coverUrl] => ) CdProduct is a subclass of ShopProduct CdProduct is a subclass of incidental CdProduct is an interface of incidental
call方法
<?php class OtherShop { function thing() { print "thing\n"; } function andAnotherthing() { print "another thing\n"; } } class Delegator { private $thirdpartyShop; function construct() { $this->thirdpartyShop = new OtherShop(); } function call( $method, $args ) { // 当调用未命名方法时执行call方法 if ( method_exists( $this->thirdpartyShop, $method ) ) { return $this->thirdpartyShop->$method( ); } } } $d = new Delegator(); $d->thing(); ?>
output:
thing
传参使用
<?php class OtherShop { function thing() { print "thing\n"; } function andAnotherthing( $a, $b ) { print "another thing ($a, $b)\n"; } } class Delegator { private $thirdpartyShop; function construct() { $this->thirdpartyShop = new OtherShop(); } function call( $method, $args ) { if ( method_exists( $this->thirdpartyShop, $method ) ) { return call_user_func_array( array( $this->thirdpartyShop, $method ), $args ); } } } $d = new Delegator(); $d->andAnotherThing( "hi", "hello" ); ?>
output:
another thing (hi, hello)
The above is the detailed content of Summary of code examples of some classes in PHP object-oriented. For more information, please follow other related articles on the PHP Chinese website!

php把负数转为正整数的方法:1、使用abs()函数将负数转为正数,使用intval()函数对正数取整,转为正整数,语法“intval(abs($number))”;2、利用“~”位运算符将负数取反加一,语法“~$number + 1”。

实现方法:1、使用“sleep(延迟秒数)”语句,可延迟执行函数若干秒;2、使用“time_nanosleep(延迟秒数,延迟纳秒数)”语句,可延迟执行函数若干秒和纳秒;3、使用“time_sleep_until(time()+7)”语句。

php除以100保留两位小数的方法:1、利用“/”运算符进行除法运算,语法“数值 / 100”;2、使用“number_format(除法结果, 2)”或“sprintf("%.2f",除法结果)”语句进行四舍五入的处理值,并保留两位小数。

判断方法:1、使用“strtotime("年-月-日")”语句将给定的年月日转换为时间戳格式;2、用“date("z",时间戳)+1”语句计算指定时间戳是一年的第几天。date()返回的天数是从0开始计算的,因此真实天数需要在此基础上加1。

php字符串有下标。在PHP中,下标不仅可以应用于数组和对象,还可应用于字符串,利用字符串的下标和中括号“[]”可以访问指定索引位置的字符,并对该字符进行读写,语法“字符串名[下标值]”;字符串的下标值(索引值)只能是整数类型,起始值为0。

在php中,可以使用substr()函数来读取字符串后几个字符,只需要将该函数的第二个参数设置为负值,第三个参数省略即可;语法为“substr(字符串,-n)”,表示读取从字符串结尾处向前数第n个字符开始,直到字符串结尾的全部字符。

方法:1、用“str_replace(" ","其他字符",$str)”语句,可将nbsp符替换为其他字符;2、用“preg_replace("/(\s|\ \;||\xc2\xa0)/","其他字符",$str)”语句。

php判断有没有小数点的方法:1、使用“strpos(数字字符串,'.')”语法,如果返回小数点在字符串中第一次出现的位置,则有小数点;2、使用“strrpos(数字字符串,'.')”语句,如果返回小数点在字符串中最后一次出现的位置,则有。


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