// function fly() {
//     echo "I can fly";
// }

class FirstClass 
{
    public $name = '小明';

    function fly() {
        echo "I can fly";
    }
}

$first = new FirstClass();

var_dump($first);//查看返回的类型是什么？

$first -> fly();//调用类中的方法

$name = '小明';//这是原来的变量声明
class FirstClass 
{
    public $name = '小明';//放在类里面就成了类的属性
                         //不写public报错,因为我们写的不全,类有类的权限控制,需要写public
    function fly() {
        echo "I can fly";
    }
}

$name = $first -> name;
$first -> fly();

<?php
class Person
{
    public $name = '隔壁大老李';

    public function learnPHP()
    {
        //伪变量(假变量,替代品,代表谁在说话)
        echo $this->name . "is learning PHP!";
    }
}

$laoli = new Person(); //$this谁调用就是谁.谁实例化就是谁

$name = $laoli->name;

echo "$name";

$laoli->learnPHP();

<?php 

class Baby {
    function __construct() {
        echo "5555555~~~~~~~";
    }
}

$baby = new Baby();

  public function __destruct(){
      echo 'die';
      }
        

class A
{

}
class B extends A
{

}

class GrandFather
{
    public $money = 3000000;
    public function par()
    {
        echo $this->money, '<br>';
    }
}

class Father extends GrandFather
{
    public function sub()
    {
        echo $this->money, '<br>';
    }
}
$wo = new Father();
$wo->par(); //父类可以调用,
$wo->sub(); //自己的也可以用
echo "$wo->money"; //继承类无法调用

 final public function myFunc() {
        echo "看你还能不能重写！";
    }
 public function myFunc() {
        echo '我把你重写了,就不给你钱';
    }

class ATM
{
    protected $money = 50000;
    protected $pass = 666;

    protected function getPass()
    {
        return $this->$this->pass;
    }

    public function verifyPass($pswd)
    {
        return $pswd == $this->pass;
    }

    public function checkOutMoney()
    {
        return $this->money;
    }
}

$atm = new ATM();

$myPass = 666;

$res = $atm->verifyPass($myPass);
var_dump($res);

$atm -> getPass();

class MySql
{
    public $link;

    public function __construct()
    {
        $this->con();
    }

    protected $cfg = array(
        'host' => '127.0.0.1',
        'user' => 'root',
        'pwd' => '',
        'db' => 'phpblog',
        'charset' => 'utf8',
    );

    public function con()
    {
        $this->link = mysqli_connect($this->cfg['host'], $this->cfg['user'], $this->cfg['pwd'], $this->cfg['db']);
        if (mysqli_connect_errno($this->link)) {
            echo "连接 MySQL 失败: " . mysqli_connect_error();
        } else {
            echo "连接 MySQL 成功";
            mysqli_query($this->link, 'set names ' . $this->cfg['charset']);
        }
    }

}

$mysql = new MySql();