OOP面向对象基础

class Person
{
    //成员变量
    public $name = '小小';
    public $sex;
    //成员方法
    public function say(){
        echo "this is ".$this -> name ;
    }
}
$ww = new Person;
$ww ->name='xxx';//成员属性的赋值
$ww ->say();//展示成员方法

//魔术方法,进入此类后直接执行此方法
 public function __construct($name,$price)
    {
        $this->name =$name;
        $this->price=$price;
    }
//传统方法,类名与函数名相同
//public function Car($name,$price){
//        $this->name =$name;
//        $this->price=$price;
//    }

  public function __construct($name,$color,$price)
    {
        $this ->name =$name;
        $this ->color = $color;
        $this ->price = $price;
        echo "this is a ".$this->name;
        echo "最先进入";
    }
    public function __destruct()
    {
        echo "最后出来";
    }
}
$bm = new Car('宝马','黄色','888888');
//unset($bm);删除后,直接执行结束,后面语句据需执行
echo "
测试
";

class Car
{
    public $name;
    public function __construct($name)
    {
        $this->name=$name;
        echo "车名为".$this->name;
        echo "进入
";
    }

    public function __destruct()
    {
        echo  $this->name."退出
";
    }
}

//$a1 = new Car('宝马');
//$a2 = new Car('兰博');
//$a3 = new Car('海马');
//车名为宝马进入
//车名为兰博进入
//车名为海马进入
//海马退出
//兰博退出
//宝马退出
$a1 = new Car('宝马');
$a2 = new Car('兰博');
unset($a2);
$a3 = new Car('海马');
//车名为宝马进入
//车名为兰博进入
//兰博退出
//车名为海马进入
//海马退出
//宝马退出

class A{
}
class B{
}

$a = new A;
$b = new A;
$c = new B;
$d = $a;
if ($a==$d){
    echo "yes";
}else{
    echo "no";
}
//两个等于,判断的是是否是同一类
//三个等于,判断的是是否是同一对象
//$a==$b  yes
//$a===$b  no
//$a==$c  no
//$a===$c  no
//$a===$d  yes