参考资料：PHP类中self和$this的区别

self：类本身的指针，$this：对象本身的指针

• self即类本身，类本身的静态属性及静态方法是占有内存的，self与$this指向的是不同的内存（即不共享任何属性）本例中 self:: = Demo::
• 以新对象为前提：new self($a) = new static($a) = $this;

代码

<?php
class Demo{public $a=1;public $b;public static $c = 1;public function __construct($a){
        $this->a = $a;}public function func(){
        echo new self(10) == new static(10);echo "\n";//1echo new self(10) == $this;//1}public function funct(){echo self::$c *= 200;echo "\n";echo Demo::$c *= 200;echo "\n";}

}
$demo = new Demo(10);
$demo->func();echo "\n";//全新对象对比，结果 1
$demo->funct();echo "\n";//self 对静态属性计算 200
$demo->func();echo "\n";//重新对比 结果 1
$demo2 = new Demo(10);
$demo2->funct();echo "\n"; //self 对静态属性计算 40000

结果

E:\server\wwwroot\php_frame_study>php test.php

1

1

200

40000

1

1

8000000

1600000000