dongxi3911 2016-06-01 10:11
浏览 16
已采纳

类继承PHP [私有vs保护和公共]

Example code 1:

<?php
class People
{
    private function status() {return __METHOD__;}
    public function Sleep(){
        echo $this->status().'<br />';
    }
}
class Programmer extends People
{
    private function status() {return __METHOD__;}
}
$obj = new Programmer();
$obj->Sleep();
?>

Printed:People::status

Example code 2:

<?php
class People
{
    protected function status() {return __METHOD__;}
    public function Sleep(){
        echo $this->status().'<br />';
    }
}
class Programmer extends People
{
    protected function status() {return __METHOD__;}
}
$obj = new Programmer();
$obj->Sleep();
?>

Printed:Programmer::status

All different in modifier methods private and protected.

Why in first case i get People::status? Why i did not get Programmer::status.

Explain me please, i don't understand this moment.

  • 写回答

1条回答 默认 最新

  • doujingxi3356 2016-06-01 10:29
    关注

    Because in the first case the Sleep method still exists only within People part of the object and cannot access Programmer::status because it is private in Programmer part of the object, but it have another method with that name available and not overwritten, the People::status.

    In the second case protected allows Programmer::status to overwrite People::status

    Yes, like this it is possible for two methods of the same name to exist in one object, but each one visible only to methods from the same class definition.

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
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