How to carry out some kind of session with a user when using a Telegram bot?

Question

Messengers

Hi all! Comrades, a very important question to understand in writing a Telegram bot. I write in PHP. And a question - how to carry out a certain similarity of session with the user? Those. I calmly determine the user by chat-id. But it is not at all clear how to store the system state (history) of communication with the user. Let's say I have 3 questions that I want to ask a user: what is your name, your age and your city. The bot sends the user "What is your name?", the user drives in his name, but how do I understand that this is the answer to my question about age, and not to some other one? As far as I understand, the system does not remember what the bot wrote (what question it asked). Thank you very much in advance!

Answer 1

Everything is simple there
Create a table and store the history by user id, or rather the last question asked and the key true, false - answered, not answered
This is as an option

Answer 2

There have been many similar questions. See:
How to consistently get telegram bots consistent values ​​from the user?
How to accept user response in Telegram Bot?
How to fulfill a condition in PHP?

Answer 3

I do this:
When you press / start, create a clean file with the name (chat_id) or if there is already one, clear it!
The user is asked the question: What is your name?
We write the username to the file.
Then your city? - We add the city to the file through the ^ sign, for example!
and so on. And to find out where the user is, we use the simplest construction:

$data = explode("^", file_get_cintents($chat_id) );
if($data[0]){
    if($data[1]){
        if($data[2]){
         // исполняем код, если 3 значение есть
        }else{
         // исполняем код, если 2 значение есть
        }
   }else{
   // исполняем код, если 1 значение есть
   }
}else{
// Файл пустой, начит пишем в него имя!
}

Everything is really very simple!