Array: set value using dot notation?

Question

Looking into Kohana documentation, i found this really usefull function that they use to get values from a multidimensional array using a dot notation, for example:

$foo = array('bar' => array('color' => 'green', 'size' => 'M'));
$value = path($foo, 'bar.color', NULL , '.');
// $value now is 'green'

Im wondering if there is a way to set the an array value in the same way:

set_value($foo, 'bar.color', 'black');

The only way i found to do that is re-building the array notation ($array['bar']['color']) and then set the value.. using eval.

Any idea to avoid eval?

Answer 1

Sure it's possible.

The code

function set_value(&$root, $compositeKey, $value) {
    $keys = explode('.', $compositeKey);
    while(count($keys) > 1) {
        $key = array_shift($keys);
        if(!isset($root[$key])) {
            $root[$key] = array();
        }
        $root = &$root[$key];
    }

    $key = reset($keys);
    $root[$key] = $value;
}

How to use it

$foo = array();
set_value($foo, 'bar.color', 'black');
print_r($foo);

Outputs

Array
(
    [bar] => Array
        (
            [color] => black
        )

)

See it in action.