PHP - 在函数中定义类 [英] PHP - defining classes inside a function

问题描述

这是不好的做法吗？

like：

function boo(){
  require_once("class.moo.php");
}
...

？

推荐答案

是这是不好的做法;

您可能会得到这两个答案，原因如下：

You're likely going to get both answers, and here's why:

如果使用 __ autoload （或等价物），则调用：

If you use __autoload (or equivalent), calling:

function someFunc()
{
  $n = new UndefinedClassName();
}

等效于：

function someFunc()
{
  include('path/to/UndefinedClassName.php');
  //may be require_once, include_once, include, or require
  //depending on how autoload is written
  $n = new UndefinedClassName();
}

但是如果你避免使用 __ autoload 。为了保持你的代码，最好将所有包含放在脚本的顶部，就像 import

But you'll get better performance out of your code if you avoid using __autoload. And to maintain your code, it's better to put all your includes at the top of the script like you would for import statements in other languages.

include('path/to/UndefinedClassName.php');
...code...
function someFunc()
{
  $n = new UndefinedClassName();
}

我建议一致性。如果你一直调用函数中的 include ，你不应该有太多的问题，但我会选择导入在文件的开头，或者 autoloads 。

I would suggest consistency. If you consistently call the include in the functions, you shouldn't have too many issues, but I would choose imports at the beginnings of files, or as autoloads.

这篇关于PHP - 在函数中定义类的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！