2019.6.14作业

<?php

// 关键词: 访问控制符, public, protected, private

// 1. public: 默认, 类内,类外,子类都可见
// 2. protected: 类内, 子类可见, 类外不可见
// 3. private: 类内可见, 子类, 类外不可见

class Demo1{
   public $name ;
   protected $dept;
   private $salary;

   public function __construct($name,$dept,$salary)
   {
       $this->name=$name;
       $this->dept=$dept;
       $salary->salary=$salary;
   }


   public function getDept(){
       return $this->dept ==='技术部'?$this->dept:'无权查看';
   }

   public function getSalary(){
       return $this->dept==='财务部'?$this->salary:'无权查看';
   }
}


$obj = new Demo1('超', '技术部', 9999);
$obj1 = new Demo1('高', '财务部', 6666);

echo $obj->name, '<br>';
echo $obj->dept, '<br>';//外部不能访问
echo $obj->salary,'<br>';//外部不能访问

echo $obj->getPosition(), '<br>';
echo $obj1->getPosition(), '<br>';

echo $obj->getSalary(), '<br>';
echo $obj1->getSalary(), '<br>';


class Demo2 extends Demo1{
   public function salary(){
       return $this->salary;
   }
}

$obj3 = new Demo2('超','技术部',8888);
echo $obj3->salary();//子类不允许访问private变量