Question

我是php的OOP概念的新手。我已经创建了这样一个类

<?Php
  class ShopProductWriter {
    public function write( $shopProduct ) {
    $str = "{$shopProduct->title}: " .
            $shopProduct->getProducer() .
           " ({$shopProduct->price})\n";
    print $str;
    }
  }

  $product1 = new ShopProduct( "My Antonia", "Willa", "Cather", 5.99 );
  $writer = new ShopProductWriter();
  $writer->write( $product1 );
?>

这里我得到的错误如Fatal error: Class 'ShopProduct' not found in line 11实际上我正在从教程中做这个例子。有人告诉我错误的部分在哪里。我的确与教程完全相同。

Answer 1

你还需要定义一个ShopProduct类：

class ShopProduct 
{
    public $title;
    public $price;        

    public function __construct( $title, $value1, $value2, $price)
    {
        $this->title = $title;
        $this->price= $price;
    }
}

Answer 2

您创建了ShopProduct类的新实例，尽管您没有定义它。您只声明了ShopProductWriter而不是ShopProduct。这就是$writer = new ShopProductWriter();有效且$product1 = new ShopProduct( "My Antonia", "Willa", "Cather", 5.99 );不起作用的原因。

这个php类有什么问题

2 个答案: