PHP/function variable - Revision history

Woozle at 18:27, 10 April 2022

2022-04-10T18:27:44Z

@@ Line 29: / Line 29: @@
 </syntaxhighlight>
 Unlike with predefined functions, however, the type for the variable is '''Callable''' rather than '''string'''.
 ==Documentation==
 * [https://www.php.net/manual/en/langref.php Language Reference]:

Woozle at 17:40, 10 April 2022

2022-04-10T17:40:58Z

← Older revision		Revision as of 17:40, 10 April 2022
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	The variable can be used to call the function in exactly the same way as if it had been assigned an anonymous function.		The variable can be used to call the function in exactly the same way as if it had been assigned an anonymous function.
	===Anonymous Functions===		===Anonymous Functions===
			<small>''[https://www.php.net/manual/en/functions.anonymous.php official documentation]''</small>
	<syntaxhighlight lang=php>		<syntaxhighlight lang=php>
	$fEx3 = function() { echo "Anonymous function was called!\n"; };		$fEx3 = function() { echo "Anonymous function was called!\n"; };

Woozle at 17:38, 10 April 2022

2022-04-10T17:38:22Z

← Older revision		Revision as of 17:38, 10 April 2022
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	==About==		==About==
	A variable can store a reference to a function. The thing that isn't explained very well in the documentation is that ~~this~~ just ~~consists~~ of ~~naming~~ the function ~~in a callable way~~.		A variable can store a reference to a function, which can then be called from the variable.
			===Named Functions/Methods===
			The thing that isn't explained very well in the documentation is that if you want to assign a ''predefined'' function to a variable, you just use a string which is a callable/accessible form of the function.
	<syntaxhighlight lang=php>		<syntaxhighlight lang=php>
	function Example1() { echo "Example1 was called!\n"; }		function Example1() { echo "Example1 was called!\n"; }
Line 19:		Line 21:
	$fEx2(); // prints "Test1 was called!"		$fEx2(); // prints "Test1 was called!"
	</syntaxhighlight>		</syntaxhighlight>
			The variable can be used to call the function in exactly the same way as if it had been assigned an anonymous function.
			===Anonymous Functions===
			<syntaxhighlight lang=php>
			$fEx3 = function() { echo "Anonymous function was called!\n"; };
			$fEx3(); // prints "Anonymous function was called!"
			</syntaxhighlight>
			Unlike with predefined functions, however, the type for the variable is '''Callable''' rather than '''string'''.
	==Documentation==		==Documentation==
	* [https://www.php.net/manual/en/langref.php Language Reference]:		* [https://www.php.net/manual/en/langref.php Language Reference]:

Woozle: Created page with "==About== A variable can store a reference to a function. The thing that isn't explained very well in the documentation is that this just consists of naming the function in a..."

2022-04-10T16:49:49Z

Created page with "==About== A variable can store a reference to a function. The thing that isn't explained very well in the documentation is that this just consists of naming the function in a..."

New page

==About==
A variable can store a reference to a function. The thing that isn't explained very well in the documentation is that this just consists of naming the function in a callable way.
<syntaxhighlight lang=php>
function Example1() { echo "Example1 was called!\n"; }

#$fEx1 = Example1; // does not work; sees "Example1" as a constant
$fEx1 = 'Example1';

$fEx1(); // prints "Example1 was called!"
</syntaxhighlight>

<syntaxhighlight lang=php>
class cExample2 {
static public function Test1() { echo "Test1 was called!\n"; }
}

#$fEx2 = cExample2::Test1; // does not work; sees "Test1" as a class constant
$fEx2 = 'cExample2::Test1';
$fEx2(); // prints "Test1 was called!"
</syntaxhighlight>
==Documentation==
* [https://www.php.net/manual/en/langref.php Language Reference]:
** [https://www.php.net/manual/en/language.types.php Types]:
*** [https://www.php.net/manual/en/language.types.callable.php '''Callbacks / Callables''']
** [https://www.php.net/manual/en/language.functions.php Functions]:
*** [https://www.php.net/manual/en/functions.anonymous.php '''Anonymous functions''']
*** [https://www.php.net/manual/en/functions.variable-functions.php '''Variable functions''']
*** [https://www.php.net/manual/en/functions.arguments.php '''Function arguments''']
* [https://www.php.net/manual/en/funcref.php Function Reference]:
** [https://www.php.net/manual/en/refs.basic.vartype.php Variable and Type Related Extensions]:
*** [https://www.php.net/manual/en/book.funchand.php Function Handling]:
**** [https://www.php.net/manual/en/ref.funchand.php Function handling Functions]:
***** [https://www.php.net/manual/en/function.call-user-func.php '''call_user_func'''()]