class类属性变量和类方法函数

<?php

class Animal {
    public $name = "小黑";
    public $age = 1;
    public function eat($name): void
    {
        echo $name . "在吃饭";
    }
}
$cat = new Animal;
echo $cat->name;
echo $cat->age;
echo $cat->eat("小红");