小编use*_*396的帖子

使用PHP,当我调用类的实例时,我会收到一个未定义的变量通知.我用其他语言编程,但不太熟悉PHP,你能不能看看我的代码并告诉我在定义类变量时的错误？谢谢.

<?php
    // create class Bike
    class Bike
    {
        // create variables for class Bike of price, max_speed, and miles
        var $price;
        var $max_speed;
        var $miles;

        // create constructor for class Bike with user set price and max_speed
        function __construct($price, $max_speed)
        {
            $this->price = $price;
            $this->max_speed = $max_speed;
        }

        // METHODS for class Bike:
        // displayInfo() - have this method display the bike's price, maximum speed, and the total miles driven
        function displayInfo()
        {
            echo "Price: $" . $price . …