


Detailed explanation of the differences between PHP object-oriented private, protected and public
This article mainly shares with you a detailed explanation of the differences between PHP object-oriented private, protected, and public. I hope it can help everyone.
private protected public本类内 Y Y Y 子类内 N Y Y 外部 N N Y
Note:
In java, if no parameters are written in front of the attributes/methods
that is, public/protected/private are not written, It is also possible, friendly
In PHP, if public/protected/private are not written,
is understood as public. It is recommended to develop good habits and don’t write
class Human { private $name = 'zhangsan'; protected $money = 3000; public $age = 28; public function say() { echo '我叫',$this->name,'<br />'; echo '我有',$this->money,'元钱<br />'; echo '我今年',$this->age,'岁'; } }class Stu extends Human { private $friend = '小花'; public function talk() { echo '我叫',$this->name,'<br />'; echo '我有',$this->money,'元钱<br />'; echo '我今年',$this->age,'岁<br />'; } }$ming = new Stu();echo $ming->age,'<br />'; // 28echo $ming->friend; //出错:因为类外不能调用privateecho $ming->money; //出错:因为类外不能调用protected属性$ming->talk();/** 出错: Notice: Undefined property: Stu::$name in 。。。 我有3000元钱 我今年28岁 分析原因: Undefined property: Stu::$name 这是说明:stu对象 没有name属性 但昨天说,私有的不是可以继承吗? 是可以继承过来,但系统有标记,标记其为父类层面的私有属性. 因此无权调用,导致此错发生. 可以分析出: protected 可以在 子类内访问 protected能在子类访问,本类内能否访问? 答:当然可以
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