从一个数组中抽取不同的元素

public function j() {
	$user = array(1,1,2,1,1,1,1,1,9); 
	$draw_user = []; 
	$num = 3;
	for ($i=0; $i < $num; $i++) { 
		$user_key = array_rand($user,1);
		$draw_user[] = $user[$user_key];
		$check = $user[$user_key];
		foreach ($user as $k => $v) {
			if ($v == $check) {
				unset($user[$k]); 
			}
		}
	}
}