Question

Im looking for a bit tricky thing 🙂

I have a multidimensional array like:

$array = array(
  "collection" => "departments",
  "action" => "find",
  "args" => array ("_id" => array("$in" => "{{variablename}}"))
);

I want to have the reference of value {{variablename}} in order to change it later.
It must be a recursive function because i can’t predict where {{variablename}} is on the array.

Without recursivity no probs, but with I didn’t find how I can do that.

PS: Other solutions to transform array to string or json and use replace does not interest me. I really need reference.

Answer 1

Not very pretty (also not recursive, which is a good thing), but should work:

// Input data
$array = array(
  "collection" => "departments",
  "action" => "find",
  "args" => array ("_id" => array('$in' => "{{variablename}}"))
);

// Create a stack
$stack = array(&$array);

// Loop until the stack is empty
while (sizeof($stack) > 0) {
    // Get the first variable in the stack (by reference)
    foreach ($stack as &$current) break;
    // Remove the first variable from the stack (by reference, same as array_shift but array_shift breaks the references) 
    $stack = array_slice($stack, 1);
    // If the shifted variable is an array
    if (is_array($current)) {
        // Add all the array's values to the stack (by reference)
        foreach ($current as &$value) {
            $stack[] =& $value;
        }
    } 
    // If the shifted variable is the one we want
    elseif ($current == '{{variablename}}') {
        // Stop the loop, leaving $current as the reference to the variable we want
        break;
    }
}
$current = 'test';
var_dump($current);
var_dump($array);

Example: http://ideone.com/hEzZk