When php parse a file,it looks for opening and closing tag.php parser interpreting the code between opening and closing tag and allows php to be embedded in all shorts of different documents.Outside of opening and closing tag is ignored by the php parser.
Now php recommended you to use only two tags.
1.Standard tag which is <?php echo "I'm Standard tag"; ?>
2.Short echo tag which is <?= "I'm Short echo tag"; ?>
Both are not affected by php ini configuration file directive.
Although php also allow short open tag which is discoursed but still available if php was configured with --enable-short-tags or short_open_tag is enabled in php ini configuration file directive.
if you want to use php in combination with xml,you can disable short_open_tag in order to use <?xml ?> inline.
Otherwise, you can print it with PHP, for example: <?php echo '<?xml version="1.0"?>'; ?>
short_echo_tag also affected the short echo tag before 5.4.0
since 5.4.0,short echo tag is always available.
asp tag <% %> and <%= > are removed from php 7
script tag <script language="php"> <script/> also removed from php 7
It is preferable to omit the closing tag if a file only contain the php code.
<?php echo "a statement";
echo "another statement";
It prevent unwanted whitespace or new line being added after the closing tag.
--happy-gazi|php-
add a note
User Contributed Notes 3 notes
anisgazig at gmail dot com ¶
2 months ago
mojtaba ¶
1 month ago
این توضیح فارسی است || this note is persian
برای شروع کد زدن پی اچ پی از تگ
<?php ?>
استفاده میکنیم
تگ فوق استاندارد است
همچنین میتوانیم از
<? ?>
استفاده کنیم که درون کد های اچ تی ام ال کاربرد وسیع دارد
همچنین میتوانیم از تگ
<! !>
استفاده کنیم که باید در قسمت کانفیگ آپاچی آن را ست کنیم که البته توصیه نمیشود.
crazytonyi at gmail dot com ¶
4 years ago
Regarding earlier note by @purkrt :
> I would like to stress out that the opening tag is "<?php[whitespace]", not just "<?php"
This is absolutely correct, but the wording may confuse some developers less familiar with the extent of the term "[whitespace]".
Whitespace, in this context, would be any character that generated vertical or horizontal space, including tabs ( \t ), newlines ( \n ), and carriage returns ( \r ), as well as a space character ( \s ). So reusing purkrt's example:
<?php/*blah*/ echo "a"?>
would not work, as mentioned, but :
<?php /*php followed by space*/ echo "a"?>
will work, as well as :
<?php
/*php followed by end-of-line*/ echo "a"?>
and :
<?php /*php followed by tab*/ echo "a"?>
I just wanted to clarify this to prevent anyone from misreading purkrt's note to mean that a the opening tag --even when being on its own line--required a space ( \s ) character. The following would work but is not at all necessary or how the earlier comment should be interpreted :
<?php
/*php followed by a space and end-of-line*/ echo "a"?>
The end-of-line character is whitespace, so it is all that you would need.
