致命错误： 调用未定义的方法 ShopProduct编写器：：获取生产者（）

Question

我遇到了一个问题：

致命错误： 调用未定义的方法 ShopProductWriter：：getProducer（） 在 C：\OSPanel\域\zandstra.com\索引.php第 37 行

是什么原因造成的？

<?php

class ShopProduct {

    public $title;

    public $producerSurName;

    public $producerFirstName;

    public $price = 0;

    public function __construct (

        $title,

        $firstName,

        $surName,

        $price

    )

    {

        $this->title = $title;

        $this->producerFirstName = $firstName;

        $this->producerSurName = $surName;

        $this->price = $price;

    }

    public function getProducer () {

        return $this->producerFirstName . " " . $this->producerSurName;

    }

}

$product1 = new ShopProduct (

    "My Antonia",

    "Willa",

    "Cather",

    "5.99"

);

class ShopProductWriter {

    public function write ($shopProduct){

        $str=$shopProduct->title . ":" . $shopProduct->getProducer()

            . " (".$shopProduct->price.")\n";

        print $str;

    }

}

$product1 = new ShopProductWriter("My Antonia", "Willa", "Cather", 5.99);

$writer = new ShopProductWriter();

$writer->write($product1);

Answer 1

这里$product1 = new ShopProductWriter("My Antonia", "Willa", "Cather", 5.99);你重新创建了 ，直到那时是一个.由此，是一个对象。这没有方法，它只有一种方法。这是你代码中的一个拼写错误，我认为你已经多次重写了你的代码，一些旧的初始化离开了，你应该已经离开了。在这种形式下，可能做你想要的：$product1ShopProduct$product1ShopProductWritergetProducer()write()<?phpclass ShopProduct {&nbsp; &nbsp; public $title;&nbsp; &nbsp; public $producerSurName;&nbsp; &nbsp; public $producerFirstName;&nbsp; &nbsp; public $price = 0;&nbsp; &nbsp; public function __construct (&nbsp; &nbsp; &nbsp; &nbsp; $title,&nbsp; &nbsp; &nbsp; &nbsp; $firstName,&nbsp; &nbsp; &nbsp; &nbsp; $surName,&nbsp; &nbsp; &nbsp; &nbsp; $price&nbsp; &nbsp; )&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; $this->title = $title;&nbsp; &nbsp; &nbsp; &nbsp; $this->producerFirstName = $firstName;&nbsp; &nbsp; &nbsp; &nbsp; $this->producerSurName = $surName;&nbsp; &nbsp; &nbsp; &nbsp; $this->price = $price;&nbsp; &nbsp; }&nbsp; &nbsp; public function getProducer () {&nbsp; &nbsp; &nbsp; &nbsp; return $this->producerFirstName . " " . $this->producerSurName;&nbsp; &nbsp; }}class ShopProductWriter {&nbsp; &nbsp; public function write ($shopProduct){&nbsp; &nbsp; &nbsp; &nbsp; $str=$shopProduct->title . ":" . $shopProduct->getProducer()&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; . " (".$shopProduct->price.")\n";&nbsp; &nbsp; &nbsp; &nbsp; print $str;&nbsp; &nbsp; }}$product1 = new ShopProduct("My Antonia", "Willa", "Cather", 5.99);$writer = new ShopProductWriter();$writer->write($product1);