This question already has answers here:
What does # mean in PHP? [duplicate]
(5 answers)
Closed 8 years ago.
I am a newbie in PHP.
I do not know the meaning of #, for example:
$key = #$_REQUEST['key'];
I have searched in google but can not find anything.
Some help me! Please !
The # symbol tells the function to fail silently instead of dumping some sort of error message. It is listed under error control operators in the PHP manual.
It suppresses any errors that the line would normally produce. In this case if the key doesn't exist, an error will occur but the error text will be silenced.
It suppresses errors and warnings.
You've found the error control operator!
It suppresses warnings in PHP. In that example it could be used to suppress and undefined index warning, if $_REQUEST['key'] doesn't exist. It's usually better practice to write:
$key = isset($_REQUEST['key']) ? $_REQUEST['key'] : 'default value for key here';
Related
This question already has answers here:
'At' symbol before variable name in PHP: #$_POST
(5 answers)
Closed 9 years ago.
Can you please tell me the difference between
$variable and #$variable in php
<?php
curl function abc
{
get information of url and return information string
}
$html=abc();
$doc=DOMDocument();
#$doc->LoadHTML($html);
?>
here if we take normal variable it gives error why its so
and whats the difference
A # before a function call means "suppress warnings".
So, #$doc->LoadHTML($html); suppresses warnings from the method call (LoadHTML()).
In general this is a bad idea, because the warnings mean you are doing something wrong, and you would better fix that instead of playing deaf.
The # operator tells the compiler to ignore the error that PHP could give, its advised not to use it.
Suppress warning when accessing that property, if for instance $html was undefined then no error is displayed, see http://davidwalsh.name/suppress-php-errors-warnings
# is called Error Control Operator, it can be prepended before expression to disable error reporting for that expression.
Please see this post for more information: Suppress error with # operator in PHP
This question already has answers here:
What is the use of the # symbol in PHP?
(11 answers)
Closed 9 years ago.
What is the meaning of ##variable in php ?
$fix=##parts;
# is used to suppress any errors that may occur on this line of the code
http://php.net/manual/en/language.operators.errorcontrol.php
When prepended to an expression in PHP, any error messages that might
be generated by that expression will be ignored.
I would not recommend using it at all because this may result in failure of noticing some important error/warning and make debugging a havoc. On a production environment use error_reporting setting that will prevent any errors or warning from showing up while on a development server I would recommend to turn on any error reporting
PHP supports one error control operator: the at sign (#). When
prepended to an expression in PHP, any error messages that might be
generated by that expression will be ignored.
Link : PHP.net explanation
The #operator turns off error handling.
This question already has answers here:
Should I use # in my PHP code?
(6 answers)
Closed 9 years ago.
Is writing:
$name = #$_GET['name'];
instead of:
$name = isset($_GET['name']) ? $_GET['name'] : null;
is some bad coding practice? Can I use # as a normal operator or only in some specific cases?
Yes, using the # operator is considered bad practice.
It is well documented that it has performance implications.
In addition, supressing error messages is a sign of bad practice; you should write your code to expect errror and handle them defensively. Simply swallowing the errors behind an # symbol means that your code will never know that the error occurred, nor what the error actually was; this can often lead to further problems later in your code.
There are some cases where it is unavoidable to use # but this is not one of them, so you should avoid doing it.
This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
Reference - What does this symbol mean in PHP?
I've seen in PHP some variables that are set like this:
$var = #$something;
Or functions set like this:
$var = &my_function();
What effect do the # and the & have?
You have them backwards. &$variable means "a reference to this variable." #my_function() means "call this function and suppress any errors or warnings that it produces."
# means "don't report errors"
& means "take a reference to the following variable instead of copying its value"
# operator in php is used to ignore errors in that statement.
Manual: http://www.php.net/manual/en/language.operators.errorcontrol.php
& is reference operator.
Manual: http://www.php.net/manual/en/language.references.whatdo.php
# causes to hide all errors. In case of variables, it might be E_NOTICE informing about variable not existing.
The &my_function(); is invalid - & is normally used for references, it doesn't nothing in this case.
This question already has answers here:
Closed 13 years ago.
Possible Duplicate:
What is the use of # symbol in php?
I like to know the purpose and meaning of # in php codes.
For instance, #umask or #ini_set. What's the difference without # and with #?
PHP's error suppress operator used to suppress error messages.
SideNote: Avoid it as much as you can, also it slows down performance heavily and not allowed to be used in ini_get and ini_set functions in future php versions.
"Swallow an error", continue despite an error occuring. An non-critical operation augmented with # will not abort script execution.
# symbol is an error control operator check out manual here