Recursion¶
Recursion in PHP is a method or a function, which calls itself.
While the method calls itself, it also must have branch and not call itself: otherwise, the call will never end.
Functions, methods, closures and arrowfunctions may be recursive.
Recursion is an abstract notion: it is also used in the PHP name itself: PHP: Hypertext Preprocessor.
<?php
function factorial(int $number) {
if ($number < 2) {
return 1;
}
return ($number * factorial($number - 1));
}
// recursive closure
$factorial = function( $n ) use ( &$factorial ) {
if( $n == 1 ) return 1;
return $factorial( $n - 1 ) * $n;
};
?>
See also All the recursive Functions in PHP.
Related : Functions, DirectoryIterator, Recursive Array, RecursiveArrayIterator
