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？<?phpclass 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()

<?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;

    }

}

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);