function drive() { echo $this->name . "正在开车" . "<br>"; } } // 医生子类 class Doctor extends Person { private $hospital, $department; function __construct($name = "", $age = "", $sex = "", $height = "", $hospital = "", $department = "") { parent::__construct($name, $age, $sex, $height); $this->hospital = $hospital; $this->department = $department; } function treat() { echo $this->name . "正在为病人治疗" . "<br>"; } } // 人 类实例化 $person1 = new Person("张三", 20, "男", 180); $person1->talk(); $person1->walk(); // 司机类实例化 $driver1 = new Driver("李四", 30, "男", 175, 8); $driver1->drive(); // 医生类实例化 $doctor1 = new Doctor("王丽", 25, "女", 167, "中国医科大学", "儿科"); $doctor1->treat();