Closure::getCurrent
(PHP 8 >= 8.5.0)
Closure::getCurrent — Returns the currently executing closure
Description
Returns the currently executing closure. This method is primarily useful for implementing recursive closures without needing to capture a reference to the closure variable using the use keyword.
This method must be called from within a closure; calling it outside of a closure context will result in Error: Current function is not a closure.
Parameters
This function has no parameters.
Return Values
Returns the currently executing Closure instance.
Errors/Exceptions
Throws an Error if called outside of a closure context.
Examples
Example #1 Closure::getCurrent() example
Using Closure::getCurrent() to implement a recursive Fibonacci function:
<?php
$fibonacci = function (int $n) {
if ($n === 0 || $n === 1) {
return $n;
}
$fn = Closure::getCurrent();
return $fn($n - 1) + $fn($n - 2);
};
echo $fibonacci(10); // Outputs: 55
?>Example #2 Comparison with traditional approach
Prior to PHP 8.5, implementing recursive closures required capturing a reference to the closure variable using the use keyword:
<?php
// Traditional approach (still works in PHP 8.5)
$fibonacci = function (int $n) use (&$fibonacci) {
if ($n === 0) return 0;
if ($n === 1) return 1;
return $fibonacci($n - 1) + $fibonacci($n - 2);
};
echo $fibonacci(10); // Outputs: 55
?>The Closure::getCurrent() approach eliminates the need to declare the variable with a reference in the use clause, making the code cleaner and less error-prone.