blocks|key|345350|text|这意味着你已经创建了一个类。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|345351|例如：|345352|class+Foo+{}

//+some+code+here

class+Foo+{}|code-block|syntax|javascript|345353|第二个Foo将抛出错误。|345354|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|O|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

It means you've already created a class.

For instance:

<pre><code>class Foo {}

// some code here

class Foo {}
</code></pre>

That second Foo would throw the error.

blocks|key|3120867|text|您多次声明了同名的类。也许可以通过多个includes。当包含其他文件时，您需要使用类似于|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3120868|include_once+"something.php";|code-block|syntax|javascript|3120869|以防止多个包含。这很容易发生，尽管并不总是显而易见的，因为你可能有一长串相互包含的文件。|3120870|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

You have a class of the same name declared more than once. Maybe via multiple includes. When including other files you need to use something like 

<pre><code>include_once "something.php";
</code></pre>

to prevent multiple inclusions. It's very easy for this to happen, though not always obvious, since you could have a long chain of files being included by one another.

blocks|key|3120933|text|当您在一个页面中多次声明一个类时，就会发生这种情况。您可以通过使用if语句包装该类来修复它(如下所示)，也可以将其放入一个单独的文件中，并使用require_once()代替include()。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3120934|if+(!class_exists('TestClass'))+{
+++//+Put+class+TestClass+here
}|code-block|syntax|javascript|3120935|entityMap^0|1Z|E|2F|9|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

That happens when you declare a class more than once in a page.
You can fix it by either wrapping that class with an if statement (like below), or you can put it into a separate file and use <code>require_once()</code>, instead of <code>include()</code>.

<pre><code>if (!class_exists('TestClass')) {
 // Put class TestClass here
}
</code></pre>

blocks|key|344132|text|如果我们使用php库中的任何内置类，就会发生这种情况。我使用类名作为Directory，我得到了同样的错误。如果出现错误，首先要确保您使用的类名不是内置的类。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|344133|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

This will happen if we use any of the in built classes in the php library. I used the class name as Directory and I got the same error. If you get error first make sure that the class name you use is not one of the in built classes.

blocks|key|344141|text|有时，这种情况是由于PHP的FastCGI中的一些bug造成的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|344142|尝试重新启动它。在Ubuntu，它是：|344143|service+php-fastcgi+restart|code-block|syntax|javascript|344144|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Sometimes that happens due to some bugs in PHP's FastCGI.

Try to restart it. At Ubuntu it's:

<pre><code>service php-fastcgi restart
</code></pre>

blocks|key|3333802|text|我也遇到过同样的问题。发现大小写是类名。我通过更改名称来处理它。因此解决了这个问题。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3333803|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

i have encountered that same problem. found out the case was the class name. i dealt with it by changing the name. hence resolving the problem.

blocks|key|3121037|text|使用include_once();+-使用此选项，您的代码将只包含一次。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3121038|entityMap^0|2|F|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

Use <code>include_once();</code> - with this, your codes will be included only one time.

blocks|key|345474|text|你使用Zend框架了吗？我也有同样的问题。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|345475|我通过在config/application.ini中注释掉下面这行代码解决了这个问题|offset|length|style|CODE|345476|;includePaths.library+=+APPLICATION_PATH+"/../library"|code-block|syntax|javascript|345477|我希望这能对你有所帮助。|345478|entityMap^0|0|4|M|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@$D|S|E|T|F|G]]|9|@]|A|$]]|$1|H|3|I|5|J|7|U|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

Did You use Zend Framework? I have the same problem too. 
I solved it by commenting out this the following line in <code>config/application.ini</code>:

<pre><code>;includePaths.library = APPLICATION_PATH "/../library"
</code></pre>

I hope this will help you.

blocks|key|346449|text|只是添加；|type|unstyled|depth|inlineStyleRanges|entityRanges|data|346450|如果您错误地将一个函数放入另一个函数中，也会发生此错误。|346451|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

Just adding;

This error can also occur if you by mistake put a function inside another function.

blocks|key|3333891|text|PHP5.3(我想也是老版本)在不同的情况下使用相同的名称似乎有问题。因此，当a具有类LogIn和它实现Login的接口时，我遇到了这个问题。在我将LogIn重命名为Log_In之后，这个问题就解决了。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3333892|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

PHP 5.3 (an I think older versions too) seems to have problem with same name in different cases. So I had this problem when a had the class Login and the interface it implements LogIn. After I renamed LogIn to Log_In the problem got solved.

blocks|key|346457|text|如果多次定义__construct方法，也可能发生此错误。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|346458|entityMap^0|6|B|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

This error might also occur if you define the <code>__construct</code> method more than once.

blocks|key|349052|text|另一个可能的罪魁祸首是源代码控制和未解决的冲突。SVN可能会导致同一个类在冲突的代码文件中出现两次；它的两个可选版本(“may”和"theirs")。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|349053|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Another possible culprit is source control and unresolved conflicts. SVN may cause the same class to appear twice in the conflicted code file; two alternative versions of it ("mine" and "theirs").

blocks|key|344213|text|此函数将打印一个堆栈，告诉您它是从何处调用的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|344214|function+PrintTrace()+{
++++$trace+=+debug_backtrace();
++++echo+'<pre>';
++++$sb+=+array();
++++foreach($trace+as+$item)+{
++++++++if(isset($item['file']))+{
++++++++++++$sb[]+=+htmlspecialchars("$item[file]:$item[line]");
++++++++}+else+{
++++++++++++$sb[]+=+htmlspecialchars("$item[class]:$item[function]");
++++++++}
++++}
++++echo+implode("\n",$sb);
++++echo+'</pre>';
}|code-block|syntax|javascript|344215|在包含您的类的文件的顶部调用此函数。|344216|有时它只打印一次，即使您的类被包含了两次或更多次。这是因为PHP实际上会在执行任何代码之前解析文件中的所有顶级类，并立即抛出致命错误。要解决此问题，请将类声明包装在if(true)+{+...+}中，这将使您的类在作用域中向下移动一层。然后你应该在PHP致命错误之前得到你的两个跟踪。|offset|length|style|CODE|344217|这应该可以帮助你在一个复杂的项目中找到你的类被多次包含在哪里。|344218|entityMap^0|0|0|0|2A|G|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|V|8|@$K|W|L|X|M|N]]|9|@]|A|$]]|$1|O|3|P|5|6|7|Y|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

This function will print a stack telling you where it was called from:

<pre><code>function PrintTrace() {
 $trace = debug_backtrace();
 echo '&lt;pre&gt;';
 $sb = array();
 foreach($trace as $item) {
 if(isset($item['file'])) {
 $sb[] = htmlspecialchars("$item[file]:$item[line]");
 } else {
 $sb[] = htmlspecialchars("$item[class]:$item[function]");
 }
 }
 echo implode("\n",$sb);
 echo '&lt;/pre&gt;';
}
</code></pre>

Call this function at the top of the file that includes your class.

Sometimes it will only print once, even though your class is being included two or more times. This is because PHP actually parses all the top-level classes in a file before executing any code and throws the fatal error immediately. To remedy this, wrap your class declaration in <code>if(true) { ... }</code>, which will move your class down a level in scope. Then you should get your two traces before PHP fatal errors.

This should help you find where you class is being included from multiple times in a complex project.

blocks|key|345546|text|我在使用autoload时遇到了同样的问题，如下所示：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|345547|<?php

function+__autoload($class_name)
{
++++include+$class_name+.+'.php';
}


__autoload("MyClass1");

$obj+=+new+MyClass1();

?>|code-block|syntax|javascript|345548|在另一个班级里，有：|345549|namespace+testClassNamespace;


class+MyClass1
{

++++function++__construct()
++++{
++++++++echo+"MyClass1+constructor";
++++}
}|345550|解决方案是保持名称空间的兼容性，在我的示例中是两个文件中的namespace+testClassNamespace;。|345551|entityMap^0|4|8|0|0|0|0|T|T|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|W|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|R|$]]

I had the same problem while using <code>autoload</code> like follows:

<pre><code>&lt;?php

function __autoload($class_name)
{
 include $class_name . '.php';
}


__autoload("MyClass1");

$obj = new MyClass1();

?&gt;
</code></pre>

and in other class there was:


<pre><code>namespace testClassNamespace;


class MyClass1
{

 function __construct()
 {
 echo "MyClass1 constructor";
 }
}
</code></pre>

The sollution is to keep namespace compatibility, in my example <code>namespace testClassNamespace;</code> in both files.

blocks|key|3121177|text|我也遇到过同样的问题:更新的php版本不能处理相同文件的多个包含(作为一个库)，所以现在我必须通过一些include_once修改我的所有包含。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3121178|或者，如果你的库中没有太多的类，这个技巧可能会有所帮助……|3121179|if(+class_exists('TestClass')+!=+true+)
{
+++//your+definition+of+TestClass
}|code-block|syntax|javascript|3121180|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

I have encountered that same problem:
newer php version doesn't deal the same with multiple incluse of the same file (as a library), so now I have to change all my include by some include_once.

Or this tricks could help, if you d'ont have too much class in your library...

<pre><code>if( class_exists('TestClass') != true )
{
 //your definition of TestClass
}
</code></pre>

blocks|key|344261|text|这实际上意味着已经在页面中声明了类，并且您正在尝试重新创建它。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|344262|下面是一种简单的技术。|344263|我用以下方法解决了这个问题。希望这篇文章能对你有所帮助。|344264|if(!class_exists("testClassIfExist"))
{
++++require_once("testClassIfExist.php");
}|code-block|syntax|javascript|344265|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|O|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|P|8|@]|9|@]|A|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

It actually means that class is already declared in the page and you are trying to recreate it.

A simple technique is as follow.

I solved the issue with the following. Hope this will help you a bit.

<pre><code>if(!class_exists("testClassIfExist"))
{
 require_once("testClassIfExist.php");
}
</code></pre>

blocks|key|3121283|text|只要在包含或需要文件名时做一件事，即class.login.php。您可以这样包含它：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3121284|include_once+class.login.php+or+
require_once+class.login.php|code-block|syntax|javascript|3121285|这样它就不会抛出错误。|3121286|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Just do one thing whenever you include or require filename namely class.login.php. You can include it this way:

<pre><code>include_once class.login.php or 
require_once class.login.php
</code></pre>

This way it never throws an error.

blocks|key|3121325|text|我遇到了同样的问题"PHP致命错误:无法重新声明类XYZ.php“。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3121326|我有两个目录，像controller和model，我在这两个目录中都错误地使用了XYZ.php上传。(所以同名的文件会导致这个问题)。|offset|length|style|CODE|3121327|第一种解决方案：|3121328|在整个项目中查找，并确保只有一个类XYZ.php。|3121329|第二种解决方案：|3121330|在类中添加命名空间，以便可以使用相同的类名。|3121331|entityMap^0|0|8|A|J|5|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|S|8|@$D|T|E|U|F|G]|$D|V|E|W|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|X|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|Y|8|@]|9|@]|A|$]]|$1|L|3|M|5|6|7|Z|8|@]|9|@]|A|$]]|$1|N|3|O|5|6|7|10|8|@]|9|@]|A|$]]|$1|P|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|Q|$]]

I had the same problem &quot;PHP Fatal error: Cannot redeclare class XYZ.php&quot;.
I have two directories like <code>controller</code> and <code>model</code> and I uploaded by mistakenly XYZ.php in both directories.(so file with the same name cause the issue).
<h3>First solution:</h3>
Find in your whole project and make sure you have only one class XYZ.php.
<h3>Second solution:</h3>
Add a namespace in your class so you can use the same class name.

blocks|key|3121354|text|必须使用require_once()函数。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3121355|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

You must use require_once() function.

Does anyone know what can cause this problem?

<blockquote>
 PHP Fatal error: Cannot redeclare class
</blockquote>

PHP Fatal error: Cannot redeclare class

Ubuntu

有人知道是什么导致这个问题吗？ PHP致命错误:无法重新声明类

问PHP致命错误:无法重新声明类
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