Question

EDIT

I know I’m a new poster here, but I’m not new to StackOverflow. I’ve never seen people make up completely new solutions to problems as I’m seeing below. I provided the input, the output, and the expected output. The accepted answer will work within these guidelines.

---

I have am trying to write an array writing function that works as described below

// existing array
$config = array("preserve" => "please");

function set($key, $value){
    global $config;
    if(count($keys = explode(':', $key)) > 1){
        $key = array_shift($keys);
        while($k = array_pop($keys)){
            $value = array($k => $value);
        }
    }
    return $config[$key] = $value;   
}

// set
set("foo", "bar");
set("pokemon:trainer", "ashk");
set("pokemon:favorite", "diglett"); // overwrites pokemon:trainer :(

print_r($config);

Output

Array
(
    [preserve] => please
    [foo] => bar
    [pokemon] => Array
        (
            [favorite] => diglett
        )

)

Oh no! Who’s the pokemon trainer? Ash Ketchum has been forgotten!

---

I understand why it’s breaking, but I can’t find out how I should write this function. I sense the need for recursion, but I’m not sure how to implement it :\

Output should be

Array
(
    [preserve] => please
    [foo] => bar
    [pokemon] => Array
        (
            [trainer] => ashk
            [favorite] => diglett
        )

)

Answer 1

Now that I have over 100 rep, I can finally post this as a real answer and mark it as accepted.

This is quite a neat little snippet 🙂

// existing array
$config = array("preserve" => "please");

function set($key, $value){
    global $config;
    if(count($keys = explode(':', $key)) > 1){
        $key = array_shift($keys);
        while($k = array_pop($keys)){
            $value = array($k => $value);
        }
        // *** fixed here ***
        // merge new data with possible existing data
        if(array_key_exists($key, $config)){
            $value = array_merge_recursive($config[$key], $value);
        }
    }
    return $config[$key] = $value;   
}

// set
set("foo", "bar");
set("pokemon:trainer", "ashk");
set("pokemon:favorite", "diglett"); // no longer overwrites pokemon:trainer :)

print_r($config);