プレイヤーの名前を取得する(array_map使用)

player.php

<?php

declare(strict_types=1);

/** @var \pocketmine\Server $server */
$players = implode(", ", array_map(function (\pocketmine\Player $player): string {
    /** @var \pocketmine\Player $player */
    return $player->getName();
}, $server->getOnlinePlayers()));

var_dump($players);//string "Steve, Alex, Foo, Bar"