Why doesn't this PHP recursive function return the value?

Question

I was working on an API for ustream which returns the following array

Array
(
[results] => Array
    (
        [0] => Array
            (
                 


        

Answer 1

Your code is flawed because you need to change

recursion($value);

into

return recursion($value);

The return will take the answer back to the caller until the first caller is reached.

edit: The lesson here is that your function should ALWAYS return a value. So here is some more elaboration:

function recursion($array) {
    if (!is_array($array)) // check if what you're getting is an array!
        return null;
    foreach ($array as $key => $value) {
        if($key==='sourceChannel') {
            return $value['id'];
        }
        if (is_array($value)) {
            $result = recursion($value);
            if ($result !== null) {
                return $result;
            }
        }
    }
    return null; // this happens if all recursions are done and sourceChannel was not found
}