blocks|key|931908|text|当然5.您必须在这样的头后面添加exit()。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|931909|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|$]]

of course 5. You have to add exit() after such a header.

blocks|key|1146394|text|该值为5。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1146395|您可以使用header输出比Location标头多得多的标头，其中大多数您不希望停止代码执行。如果您想停止代码执行，则需要显式调用exit。|offset|length|style|CODE|1146396|entityMap^0|0|5|6|E|8|1T|4|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@$D|L|E|M|F|G]|$D|N|E|O|F|G]|$D|P|E|Q|F|G]]|9|@]|A|$]]|$1|H|3|-4|5|6|7|R|8|@]|9|@]|A|$]]]|I|$]]

The value is 5.

You can output a lot more headers than just <code>Location</code> headers with <code>header</code>, most of which you don't want to stop your code execution. If you want to stop code execution, you need to call <code>exit</code> explicitly.

blocks|key|1146433|text|header命令不会中断代码流。即使遇到这种情况，浏览器仍然会下载您的页面，即使它没有显示。考虑404个页面，这些页面(尽管有错误)仍然由浏览器处理(尽管它们是呈现的，而重定向不是)。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1146434|entityMap^0|0|6|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|$]]

The <code>header</code> command doesn't interrupt the flow of your code. Even if that is encountered, your page is still downloaded by the browser, even if it isn't show. Consider 404 pages, which (despite being errors) are still processed by the browser (though they are rendered while redirects are not).

blocks|key|932041|text|一旦你发出了头文件，你就开始了代码和and服务器/浏览器之间的竞争。通常，一旦浏览器接收到重定向，它就会关闭运行脚本的连接，并开始连接到新的重定向URL。当连接关闭时，web服务器通常会尝试终止脚本。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|932042|您可能很幸运，能够完成您想要做的任何其他事情，或者您可能不走运，在header()调用之后，脚本甚至无法到达下一行。|offset|length|style|CODE|932043|不过，还有一个ignore_user_abort()函数，它可以让您的脚本继续运行，而不管连接的状态如何。|932044|entityMap|0|LINK|mutability|MUTABLE|url|http://php.net/manual/en/function.ignore-user-abort.php^0|0|X|8|0|7|J|7|J|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]]|9|@]|A|$]]|$1|H|3|I|5|6|7|V|8|@$D|W|E|X|F|G]]|9|@$D|Y|E|Z|1|10]]|A|$]]|$1|J|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|K|$L|$5|M|N|O|A|$P|Q]]]]

Once you issue the header, you've started a race between your code and the webserver/browser. Generally, as soon as the browser receives the redirect, it'll close the connection that ran the script and start connecting to the new redirect URL. When the connection's closed, the web server will generally try to kill the script.

You might get lucky and be able to finish off anything else you wanted to do, or your might be unlucky and the script won't even be able to reach the next line after the <code>header()</code> call.

There is the <a href="http://php.net/manual/en/function.ignore-user-abort.php" rel="nofollow noreferrer"><code>ignore_user_abort()</code></a> function, which should let your script continue regardless of the connection's status, though.

blocks|key|932095|text|你应该总是在重定向之后死掉()或者退出()(或者正如Mark+B所指出的，使用ignore_user_abort()+)，因为你不能确定会发生什么。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|932096|虽然一些代码会在头位置重定向后执行，但重要的是要注意，并不是所有在它之后的代码都会执行。|932097|根据您的示例，是的，some_value将等于5。但是在某些情况下，脚本将被提前终止。|932098|下面是一个例子：|932099|session_start();
$_SESSION["some_value"]+=+'original+value';
header("Location:+/index.php/test2");

$start_time+=+microtime(true);

for($i+=+0;+$i+<=+100000;+$i+%2B%2B)
{
++++password_hash($i);++//+slow+it+down
++++$_SESSION["some_value"]+=+$i;+++
++++$_SESSION['time']+=+microtime(true)+-+$start_time;
}

$_SESSION['some_value']+=+'finished!';|code-block|syntax|javascript|932100|如果所有其他答案都是正确的，那么您可能会认为$_SESSION‘the+_value’等于‘完成！’--但是我运行了代码，结果并非如此。|932101|以下是我的结果：|932102|some_value:+174
time:+0.0026998519897461|932103|试验二：|932104|some_value:+218
time:+0.0033109188079834|932105|试验三：|932106|some_value:+218
time:+0.0035371780395508|932107|试验四：|932108|some_value:+174
time:+0.0026431083679199|932109|试验五：|932110|some_value:+174
time:+0.0027921199798584|932111|如果我实现了ignore_user_abort(TRUE)；在上面的脚本中，some_value就等于“完成！”所以，如果你打算做一些关键的事情，比如记录日志或数据库查询，或者在重定向后发送电子邮件，请记住这一点。|932112|entityMap^0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|1C|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|1D|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|1E|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|1F|8|@]|9|@]|A|$]]|$1|H|3|I|5|J|7|1G|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|1H|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|1I|8|@]|9|@]|A|$]]|$1|Q|3|R|5|J|7|1J|8|@]|9|@]|A|$K|L]]|$1|S|3|T|5|6|7|1K|8|@]|9|@]|A|$]]|$1|U|3|V|5|J|7|1L|8|@]|9|@]|A|$K|L]]|$1|W|3|X|5|6|7|1M|8|@]|9|@]|A|$]]|$1|Y|3|Z|5|J|7|1N|8|@]|9|@]|A|$K|L]]|$1|10|3|11|5|6|7|1O|8|@]|9|@]|A|$]]|$1|12|3|13|5|J|7|1P|8|@]|9|@]|A|$K|L]]|$1|14|3|15|5|6|7|1Q|8|@]|9|@]|A|$]]|$1|16|3|17|5|J|7|1R|8|@]|9|@]|A|$K|L]]|$1|18|3|19|5|6|7|1S|8|@]|9|@]|A|$]]|$1|1A|3|-4|5|6|7|1T|8|@]|9|@]|A|$]]]|1B|$]]

You should always die() or exit() after the redirect (or as pointed out by Mark B, use ignore_user_abort() ) because you can't otherwise know for certain what will happen.

Though some code will get executed after a header location redirect, it's important to note that not all code after it will necessarily get executed.

As per your example, yes, some_value will equal 5. But at some point the script will get prematurely terminated.

Take the following example:

<pre><code>session_start();
$_SESSION["some_value"] = 'original value';
header("Location: /index.php/test2");

$start_time = microtime(true);

for($i = 0; $i &lt;= 100000; $i ++)
{
 password_hash($i); // slow it down
 $_SESSION["some_value"] = $i; 
 $_SESSION['time'] = microtime(true) - $start_time;
}

$_SESSION['some_value'] = 'finished!';
</code></pre>

If all the other answers were correct, you'd assume $_SESSION['some_value'] would equal 'finished!' -- but I ran the code and this is not the case.

Here are my results:

<pre><code>some_value: 174
time: 0.0026998519897461
</code></pre>

Trial two:

<pre><code>some_value: 218
time: 0.0033109188079834
</code></pre>

Trial three:

<pre><code>some_value: 218
time: 0.0035371780395508
</code></pre>

Trial four:

<pre><code>some_value: 174
time: 0.0026431083679199
</code></pre>

Trial five:

<pre><code>some_value: 174
time: 0.0027921199798584
</code></pre>

If I implement ignore_user_abort(TRUE); in the above script then some_value does equal "finished!" so keep that in mind if you intend to do something critical like logging or database queries or sending emails after the redirect.

<pre><code>$_SESSION["some_value"] = 4;
header("Location: another-file.php");
$_SESSION["some_value"] = 5;
</code></pre>

what's the value of <code>$_SESSION["some_value"]</code> ?

Is code after header("Location: ...) executed?

数据库

服务器

$_SESSION["some_value"] = 4;header("Location: another-file.php");$_SESSION["some_value"] = 5;$_SESSION["some_value"]的价值是什么？

问是否执行标题(“Location：...”)之后的代码？
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问是否执行标题(“Location：...”)之后的代码？
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