Бот для Vk

$messages_array = [
'Привет' => "Привет, {$user_name}!",
];
foreach($messages_array as $k => $v){
if($message == $k){$otwet = $v;}
}

'Привет' => "Привет, пользователь."

Привет:Привет, пользователь

<?php
$confirmation_token = '***';
$token = '****';
$data = json_decode(file_get_contents('php://input'));
switch ($data->type){
case 'confirmation':
echo $confirmation_token;
break;
case 'message_new':
$user_id = $data->object->user_id;
$user_info = json_decode(file_get_contents("https://api.vk.com/method/users.get?user_ids={$user_id}&v=5.0"));
$user_name = $user_info->response[0]->first_name;
$message = $data->object->body;
$messages_array = [
'Привет' => "Привет, {$user_name}!",
];
foreach($messages_array as $k => $v){
if($message == $k){$otwet = $v;}
}
$request_params = [
'message' => $otwet,
'user_id' => $user_id,
'access_token' => $token,
'v' => '5.0'
];
$get_params = http_build_query($request_params);
file_get_contents('https://api.vk.com/method/messages.send?'. $get_params);
echo('ok');
break;
return false;
}
?>

strcasecmp

if($message == $k){$otwet = $v;}