## How Can You Implement Recursive Anonymous Functions in PHP?

Anonymous Recursive Functions in PHP

In PHP, the concept of anonymous functions, also known as lambda functions, offers a convenient way to define functions inline without specifying a formal name. However, when it comes to recursion, anonymous functions face a unique challenge.

The Issue:

When attempting to create a recursive anonymous function, it may appear that the function name is not being passed into the recursion correctly. This issue arises because, unlike regular functions with defined names, anonymous functions lack a reference to themselves.

The Solution:

To resolve this issue, you need to pass the anonymous function as a reference within the use statement. This can be achieved by adding an ampersand (&) before the function name, as demonstrated in the following code:

<code class="php">$factorial = function( $n ) use ( &amp;$factorial ) {
    if( $n <= 1 ) return 1;
    return $factorial( $n - 1 ) * $n;
};

print $factorial( 5 ); // Output: 120</code>

By passing the anonymous function as a reference, you establish a connection between the recursive call and the original function definition, allowing it to access its own internal state. This enables the recursion to function as expected, and you can successfully compute factorial values.

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