定义类

class class_name [extends partclass_name]

{

public private protected var property_name = value;

public private protected function method_name (){}

}

创建对象

$Obj = new Employee();

//使用->访问对象成员

$Obj->Name = 'Flower';

$Obj->ShowName();

Static 关键字 纯粹一般用途

class MyMath

{

public static function Cubic($x)

{

return $x*$x;

}

}

访问

echo MyMath::Cubic('5');

类常数const

class Circle

{

const PI=3.14

public $Radius;

public function ShowArea()

{

echo $this->Radius*self::PI;

}

$Obj = new Circle();

$Obj->Radius = 10;

$Obj->ShowArea();

}

构造函数和析构函数

function _construct($str){$this->Name = $str;}

function _destruct(){$this->Name = NULL}

//PHP7 匿名类

$Obj = new class('小红豆')

{

public $Name;

function _construct($){$this->Name = $str;}

}

继承 extends关键字

覆盖 override

调用父类 parent::

方法前加final 表示子类不能覆盖子类成员

namespace \

namespace my\name

use my\name as MN;//命名空间别名