php - 如何解决注意：php中未定义的变量错误

Question

我目前正在 php 中创建一个名为 Pizza 的类，它具有两个属性：名称和价格。

    <?php
    
    class Pizza{
        private $name;
        private $price;
    
        public function __construct($name, $price){
            $this->setName($name);
            $this->setPrice($price);
        }
    
        public function getName(){
            return $this->$name;
        }
    
        public function getPrice(){
            return $this->$price;
        }
    
        public function setName($name){
            $this->$name = $name;
        }
    
        public function setPrice($price){
            $this->$price = $price;
        }
    }
    
    $pizza1 = new Pizza('pepperoni', 10);
    $pizza1->getPrice();

但是当我为价格调用 getter 方法时，我一直有这些错误：

( ! ) Notice: Undefined variable: price in C:\wamp\www\pw\crazy pizza\pizza.php on line 17
Call Stack
#   Time    Memory  Function    Location
1   0.0020  391472  {main}( )   ...\pizza.php:0
2   0.0020  391856  Pizza->getPrice( )  ...\pizza.php:30

( ! ) Notice: Undefined property: Pizza::$ in C:\wamp\www\pw\crazy pizza\pizza.php on line 17
Call Stack
#   Time    Memory  Function    Location
1   0.0020  391472  {main}( )   ...\pizza.php:0
2   0.0020  391856  Pizza->getPrice( )  ...\pizza.php:30

请问你知道我的代码有什么问题吗？