<?php
$data = (object) [
"Chats" => [
(object) ["Chat" => (object) ["ChatId" => 1000]],
(object) ["Chat" => (object) ["ChatId" => 2000]],
(object) ["Chat" => (object) ["ChatId" => 3000]],
(object) ["Chat" => (object) ["ChatId" => 4000]],
(object) ["Chat" => (object) ["ChatId" => 5000]],
]
];
$Chats = array_column($data->Chats, "Chat");
$ChatIds = array_column($Chats, "ChatId");
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