使用每个递归函数添加到数组[重复]

Question

This question already has an answer here:

• counting the number of times a recursive function is called 8 answers

I want to add to an array when each recursive function is called. I have played around with it a few ways, but just getting error after error. This is about where I am up to, it should be enough to work out what I am trying to accomplish.

function structure($x, $structure = array()) {
$qry = mysql_query("SELECT `parent_id` FROM `categories` WHERE `categories_id`=$x");
$result = mysql_fetch_assoc($qry);
$cat = $result['parent_id'];
if($cat !=0) {
    structure($cat, $structure[] = $cat);
}
echo $cat.' >';
return $structure;
}

echo structure(22);
var_dump($structure);

So I am also trying to return the array as well, unsuccessfully. I am not sure how you return an array from a function either.

So I would appreciate help on how to add to an array with each recursive function and return the array outside of the function into a useable variable.

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Answer 1

if($cat !=0) {
    $structure = structure($cat, $structure[] = $cat);
}

as structure() return a value, you need to set it to a variable, so this variable is fed on every call. And at the end :

$whatever = structure(22);
var_dump($whatever );