Solved Add/remove an element out of config's array?

What is the shortest code to add/remove an element out of an config's array?
Example:

Code:

worlds:
- "World1"
- "World2"
- "World3"

to

Code:

worlds:
- "World1"
- "World2"
- "World3"
- "World4"

Maybe there's something like this?

Code:

$this->getConfig()->add("anything", $myarray");

 

PHP:

$arr = $this->getConfig()->get("anything");
$arr[] = "World4";
$this->getConfig()->set("anything", $arr);