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.
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User Contributed Notes 4 notes
crazytonyi at gmail dot com ¶
3 years ago
kuzawinski dot marcin at gmail dot com ¶
1 month ago
New lines placed after PHP closing tags are ignored;
<?= "A"?>
B
<?= "C"?>
Output:
AB
C
Mark Clements (kennel17.co.uk) ¶
1 year ago
Closing PHP tags are recognised within single-line comments:
<?php
// Code will end here ?> This is output as literal text.
<?php
# Same with this method of commenting ?> This is output as literal text.
However they do not have an effect in C-style comments:
<?php
/* Code will not end here ?> as closing tags are ignored inside C-style comments. */
?>
pl at dot pl ¶
4 months ago
Omit closing tag ?> always whenever you can
example:
<!DOCTYPE html><head>
<title><?php include'varia.php'; echo$title?></title>
</head><body></body></html>
varia.php
<?php
$title = 'Welcome';
?>
[new line] //other words: an extra 'Enter' is guilty
---------------
and you get:
Welcome - at the browser label
source won't tell you what happened - there will be fine:
<!DOCTYPE html><head>
<title>Welcome</title>
</head><body></body></html>
Now imagine, what else can go wrong because of it? Everything, as Murphy said.
And you will look for the answer why...? And where...?
It's just simplest example.
