在PHP中，为什么没有显示解析错误?

I was running the following PHP code:

我运行的PHP代码如下:

<?php 
    </script>
?>

There were no parse errors and the output was "?>" (example).

没有解析错误，输出是“?”>”(例子)。

In similar cases I do get a parse error:

在类似的情况下，我确实得到了一个解析错误:

<?php 
    </div>
?>

Parse error: syntax error, unexpected '<' in ...

解析错误:语法错误，在…

Why doesn't <?php </script> ?> give the same error?

为什么不< ?php ?> ?

2 个解决方案

271

This must be because there are various ways of starting a block of PHP code:

这一定是因为有很多方法可以启动一个PHP代码块:

<? ... ?> (known as short_open_tag)
< ?…? >(称为short_open_tag)
<?php ... ?> (the standard really)
< ?php……? >(标准真的)
<script language="php"> ... </script> (not recommended)
< =“php脚本语言>…< /脚本>(不推荐)
<% ... %> (deprecated and removed ASP-style tag after 5.3.0)
< %……%>(在5.3.0之后弃用和移除asp样式的标签)

Apparently, you can open a PHP block one way, and close it the other. Didn't know that.

显然，您可以以一种方式打开一个PHP块，然后以另一种方式关闭它。不知道。

So in your code, you opened the block using <? but PHP recognizes </script> as the closer. What happened was:

在你的代码中，你使用更接近。发生了什么是:

<?php       <----- START PHP
</script>   <----- END PHP
?>          <----- JUST GARBAGE IN THE HTML