


This article mainly introduces PHP object-oriented programming and the like constants usage, which is a very important concept in PHP object-oriented programming, for PHP beginners It is even more necessary to have a firm grasp of it. Friends who need it can refer to
Class constants are a very important concept in PHP object-oriented programming. A firm grasp of class constants will help further improve the efficiency of PHP object-oriented programming. level. This article describes the usage of class constants in PHP programming in the form of examples. The details are as follows:
Class constants: In the class, data that remains unchanged during the running cycle is saved.
Definition:
const 关键字 const 常量名 = 常量值
Examples are as follows:
class Student { public $stu_id; public $stu_name; public $stu_gender; const GENDER_MALE= '男'; const GENDER_FEMALE = '女'; }
Class constants are not restricted by access qualification modifiers
Access methods:
Class::Constant name
The example is as follows:
class Student { public $stu_id; public $stu_name; public $stu_gender; const GENDER_MALE= '男'; const GENDER_FEMALE = '女'; public function construct($id,$name,$gender='') { $this->stu_id= $id; $this->stu_name= $name; $this->gender= ($gender == ' ')?self::GENDER_MALE : $gender; } }
Summary: The members that can be defined in the class are: constant, staticAttributes, non-static properties, static methods, non-static methods.
Note here:
$this represents the current object, so does it always represent the object of the class where $this belongs?
the answer is negative! Because the value of $this does not depend on the class where $this is located, but depends on the execution object (execution environment) when the method where $this is located is called.
The execution environment of the method, which object the current method is in When executed in an environment, $this in the method indicates which object.
The above is the detailed content of Detailed explanation of usage examples of object-oriented class constants in PHP. For more information, please follow other related articles on the PHP Chinese website!

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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。

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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。

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,可以利用implode()函数的第一个参数来设置没有分隔符,该函数的第一个参数用于规定数组元素之间放置的内容,默认是空字符串,也可将第一个参数设置为空,语法为“implode(数组)”或者“implode("",数组)”。


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