How to clear a players Armor inventory?

Hi, i am trying to make it so that when a player switches worlds, their armor is cleared. As currently when a player is switching worlds, forexample from a creative world to a survival one, they can take their armor with them.

What i have tried so far:

PHP:

$player->getInventory()->clearAll()

PHP:

$player->getInventory()->setContents([]);

Neither of those have helped. A players inventory is cleared but not their armor.

 

$player->getArmorInventory()->clearAll();

 

Thanks, that worked