php - PHP对象属性没有正确输出

Question

我创建了一个基本的 PHP Book 类，它应该打印出 $title、$author 和 $pages。然而，我的代码打印出 $pages 3 次，知道我做错了什么吗？

<?php
    class Book{
        var $title;
        var $author;
        var $pages;
    }

    $book1 = new Book();
    $book1 -> $title = "Oliver Twist";
    $book1 -> $author = "Charles Dickens";
    $book1 -> $pages = 373;

    echo $book1 -> $title;
    echo $book1 -> $author;
    echo $book1 -> $pages;
?>

预期输出：Oliver TwistCharles Dickens373

实际输出：400400400

标签： phpoop

Answer 1

删除 $

   class Book{
        var $title;
        var $author;
        var $pages;
    }

    $book1 = new Book();
    $book1->title = "Oliver Twist";
    $book1->author = "Charles Dickens";
    $book1->pages = 373;

    echo $book1->title;
    echo $book1 ->author;
    echo $book1 ->pages;