Code start sign type in php php7 php environment construction php from entry to proficiency

When I was looking at other people’s php code today, I found

<code><span><span><?php </span><span>$a</span>=<span>'test'</span>;
<span>?></span></span><span><span></span>=<span>$a</span><span>?></span></span></span></code>

that the result actually outputted ‘test’

So I changed the code to the following: The

<code><span><span><?php </span><span>$a</span>=<span>'test'</span>;
<span>?></span></span><span><span></span><span>echo</span><span>$a</span><span>?></span></span></span></code>

structure had nothing, so I became even more curious. Start looking for information and so on. . .
Online information:
?> is a short tag, <?php ?> is a long tag, end tags are generally rarely used, the command =, which is the same as echo is equivalent, but short_open_tag needs to be turned on before use.
What is short_open_tag?
Determines whether the abbreviated form of the code start flag ( ?> ) is allowed.
It can be configured in php.ini.
Problem: I checked my php.ini configuration file and found that short_open_tag was not turned on. As shown below:

But why can I still use = Could it be that there are multiple php.ini, I don’t know, so I checked it through phpinfo();

Found short_open_tag = Off.
So = Why can it be used but still can’t be solved?
So I will start short_open_tag, that is, set short_open_tag = On, and then restart the server. Found that

<code><span><span></span><span>echo</span><span>'hello'</span>;
<span>?></span></span></code>

can output results.
Summary: It turns out that short_open_tag controls the ?> tag. Instead of the = ?> tag, the = ?> tag is used for output variables. When short_open_tag is enabled, ?> has the same function as <?php ?>.

If asp_tags = ON is set, then we can still play like this

<code>$a=<span>'hello'</span>;
<span>echo</span><span>$a</span>;
%></code>

Remarks: The php version used is: PHP Version 5.5.12
Now to summarize, there are several opening and closing tags in PHP

• <?php
• ?>
• = ?&gt ;

').addClass('pre-numbering').hide(); $(this).addClass('has-numbering').parent().append($numbering); for (i = 1; i ').text(i)); }; $numbering.fadeIn(1700); }); });

The above introduces the code start flag types in PHP, including PHP content. I hope it will be helpful to friends who are interested in PHP tutorials.