This question already has answers here:
Closed 12 years ago.
Possible Duplicate:
Reference - What does this symbol mean in PHP?
I've been programming PHP for over 5 years and I've just came across something I have never seen whilst creating a wordpress theme.
$images =& get_children( 'post_type=attachment&post_mime_type=image' );
What does $images =& do? It's the =& I'm concerned about. I have a feeling it's bitwise but I wouldn't understand what it's doing even if it was.
Any help?
Assigns a value by reference
http://www.php.net/manual/en/language.operators.assignment.php
Assignment by reference means that
both variables end up pointing at the
same data, and nothing is copied
anywhere.
=& is the assignment by reference operator.
You can find out more about references here: http://php.net/manual/en/language.references.php
It's an assign by reference.
http://php.net/manual/en/language.references.pass.php
As opposed to a normal pass by value assignment.
Related
This question already has answers here:
Reference Guide: What does this symbol mean in PHP? (PHP Syntax)
(24 answers)
Closed 1 year ago.
I'm upgrading old in-house PHP code for my company and I stumbled upon this piece of code:
foreach ($array as $key => &$value) {
// do something
}
what's the meaning of &$value and can I safely assume this is a mistype?
It is not mistype. It is reference and it means to access the same variable content by different names. If you modify the value of $value, then you would also modify the original value inside $array.
You can read more about it at References Explained, Php.net
This question already has answers here:
Reference Guide: What does this symbol mean in PHP? (PHP Syntax)
(24 answers)
Closed 7 years ago.
I want to know about meaning of $$val; what is the actual meaning is?i tried to find meaning of this in google but not understand properly. Please help me in this situations.
For example: suppose i have one variable which has $$value;
meaning of $$value?
You didn't put the language, but I'll assume you mean PHP
That's a variable variable.
That means you ware asking for the value of the variable whose name.is the first variable.
Here's an example, since that's quite confusing:
$foo = "Hi";
$bar = "world";
$world = "Hello!";
echo $$bar; // "Hello!"
php fiddle: http://ideone.com/Ve4YOO
Reference: https://secure.php.net/manual/en/language.variables.variable.php
This question already has answers here:
What does it mean to start a PHP function with an ampersand?
(3 answers)
Closed 7 years ago.
I'm using a CMS package written in PHP. In one of it's core files I saw following line that is for defining a function in a class body.
public static function &getLib($sClass, $aParams = array()) {
// Code
}
I didn't understand why the function name 'getLib' has been prepended with the ampersand(&) sign? I've never seen such thing before.
Can someone please explain me in detail why such thing has been done and what's the benefit it has over simply using the function name?
It means the function should return a reference to a variable rather than just the value itself.
This question already has answers here:
Reference Guide: What does this symbol mean in PHP? (PHP Syntax)
(24 answers)
Closed 8 years ago.
Can you please explain to me the differences between two functions:
function &a(){
return something;
}
and
function b(){
return something;
}
Thanks!
The first returns a reference to something, the second a copy of something.
In first case, when the caller modify the returned value, something will be modified as a global variable do.
In the second case, modifying a copy as no effect to the source.
An ampersand before a function name means the function will return a reference to a variable instead of the value.
According to this LINK
Returning by reference is useful when you want to use a function to find to which
variable a reference should be bound. Do not use return-by-reference to increase
performance. The engine will automatically optimize this on its own. Only return
references when you have a valid technical reason to do so.
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
What does “=>” mean in PHP?
Reference - What does this symbol mean in PHP?
I see this symbol in a lot of PHP code.
I can't figure out what it means or what it does..
Is it really an operator ?
Do you mean =>? If so, it's for initializing array keys (or indexes if you prefer). Like this:
$values = array(
'foo' => 'bar'
);
This will initiazlie an array with a key named foo with a value of bar.
Read more on about arrays at php.net.
http://php.net/manual/en/language.operators.php