PHP“无法访问受保护的属性”
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PHP "cannot access protected property"
提问by Nextar
This is my first OOP program, so please don't be mad at me :) The problem is that I've got the following error:
这是我的第一个 OOP 程序，所以请不要生我的气:) 问题是我遇到了以下错误：
Cannot access protected property Code::$text in D:\xampp\htdocs\php\OOP\coder_class.php on line 47
无法访问第 47 行 D:\xampp\htdocs\php\OOP\coder_class.php 中的受保护属性 Code::$text
The program simply codes a string and decodes it. I'm not sure if this is a good example to learn OOP.
该程序只是对字符串进行编码并对其进行解码。我不确定这是否是学习 OOP 的好例子。
<?php
class Code
{
// eingabestring
protected $text;
public function setText($string)
{
$this->text = $string;
}
public function getText()
{
echo $this->text;
}
}
class Coder extends Code
{
//Map for the coder
private $map = array(
'/a/' => '1',
'/e/' => '2',
'/i/' => '3',
'/o/' => '4',
'/u/' => '5');
// codes the uncoded string
public function coder()
{
return preg_replace(array_keys($this->map), $this->map, parent::text);
}
}
class Decoder extends Code
{
//Map for the decoder
private $map = array(
'/1/' => 'a',
'/2/' => 'e',
'/3/' => 'i',
'/4/' => 'o',
'/5/' => 'u');
// decodes the coded string
public function decoder()
{
return preg_replace(array_keys($this->map), $this->map, parent::text);
}
}
$text = new code();
$text -> setText("ImaText");
$text -> coder();
$text -> getText();
?>
?>
Can some help me fixing this . Am new to PHP .
有人可以帮我解决这个问题。我是 PHP 新手。
回答by álvaro González
Relevant code:
相关代码：
class Code
{
protected $text;
}
$text = new code();
echo $text->text;
The property is not public, thus the error. It works as advertised.
该属性不是公共的，因此是错误的。它像宣传的那样工作。
回答by Sammitch
With:
和：
protected $text;
And:
和：
echo $text->text;
Is why you get the error. protectedmeans that only descendants of the Codeclass can access that property, ie. Coderand Decoder. If you want to access it via $text->textit must be public. Alternatively, just write a getText()method; you've already written the setter.
这就是为什么你得到错误。protected意味着只有Code该类的后代才能访问该属性，即。Coder和Decoder。如果你想通过$text->text它访问它必须是public. 或者，只需编写一个getText()方法；您已经编写了 setter。
Side note: the public, private, and protectedkeywords have virtually nothingto do with security. They are generally intended to enforce data/code/object integrity.
附注：在public，private和protected关键字都几乎没有什么做的安全性。它们通常用于强制执行数据/代码/对象完整性。
