PHP实现在对象之外访问其私有属性private及保护属性protected的方法

<?php
 //父类
 class father{
 public function a(){
 echo "function a<br/>";
 }
 private function b(){
 echo "function b<br/>";
 }
 protected function c(){
 echo "function c<br/>";
 }
 }
 //子类
 class child extends father{
 function d(){
 parent::a();//调用父类的a方法
 }
 function e(){
 parent::c(); //调用父类的c方法
 }
 function f(){
 parent::b(); //调用父类的b方法
 }
 }
 $father=new father();
 $father->a();
// $father->b(); //显示错误 外部无法调用私有的方法 Call to protected method father::b()
// $father->c(); //显示错误 外部无法调用受保护的方法Call to private method father::c()
 $chlid=new child();
 $chlid->d();
 $chlid->e();
// $chlid->f();//显示错误 无法调用父类private的方法 Call to private method father::b()
?>

function a
function a
function c

class yunke
{
 protected $a = 55;
 private $b = 66;
 public function merge()
 {
 $result = clone $this;
 $result->a=88;
 $result->b=99;
 return $result;
 }
 public function show()
 {
 echo $this->a;
 echo $this->b;
 }
}
$test = new yunke;
$test->show();
$test2=$test->merge();
$test2->show();

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