php类中static与self的使用区别浅析

<?php
class parents
{
    protected static $name = '我是你父母';
 
    public static function who_self()
    {
        return self::$name;
    }
 
    public static function who_static()
    {
        return static::$name;
    }
 
    public static function get_self()
    {
        return new self();
    }
 
    public static function get_static()
    {
        return new static();
    }
}
 
class kinsfolk extends parents
{
    protected static $name = '我是你亲戚';
}
 
var_dump(kinsfolk::who_self()); //我是你父母
var_dump(kinsfolk::who_static()); //我是你亲戚
var_dump(kinsfolk::get_self()); //object(parents)#1 (0) {}
var_dump(kinsfolk::get_static()); //object(kinsfolk)#1 (0) {}