How to write a yml file

I'm trying to make 2 yml files:
playerdata.yml:

Code:

Indexfire:
  Rank: Default

gamedata.yml:

Code:

Indexfire:
  Phoenix:
    -1
    -1
    -1
  Marksman:
    -1
    -1
    -1
  Desolator:
    -1
    -1
    -1

But the tutorials do not help at all, how do I achieve this? I also want to read what they contain

 

PHP:

$a["Phoenix"] = 1;
$config->set("Indexfire" , $a);


 

Assuming both YAML files are in your plugin's data folder and are running the code from the PluginBase...

PHP:

$playerData = new Config($this->getDataFolder()."playerdata.yml", Config::YAML);
$IndexfireData = $playerData->get("Indexfire", []);
var_dump($IndexfireData);
$gamedataData = new Config($this->getDataFolder()."gamedata.yml", Config::YAML);
$gamedata = $gamedataData->getAll();
var_dump($gamedata);


 

Thanks