匿名递归 PHP 函数 [英] Anonymous recursive PHP functions

问题描述

是否有可能同时具有递归和匿名的 PHP 函数?这是我试图让它工作的尝试，但它没有传入函数名.

Is it possible to have a PHP function that is both recursive and anonymous? This is my attempt to get it to work, but it doesn't pass in the function name.

$factorial = function( $n ) use ( $factorial ) {
    if( $n <= 1 ) return 1;
    return $factorial( $n - 1 ) * $n;
};
print $factorial( 5 );

我也知道这是实现阶乘的不好方法，这只是一个例子.

I'm also aware that this is a bad way to implement factorial, it's just an example.

推荐答案

为了让它工作，你需要传递 $factorial 作为参考

In order for it to work, you need to pass $factorial as a reference

$factorial = function( $n ) use ( &$factorial ) {
    if( $n == 1 ) return 1;
    return $factorial( $n - 1 ) * $n;
};
print $factorial( 5 );

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