How to put a value from another array into the key name of an associative array?

Question

JavaScript

I have a script that dynamically adds the received values ​​​​to an associative array, the array itself looks something like this:

var object = {
    _id: chatMsg['user_id'],
    chatlog: {
        msg: {
            attachments: chatMsg['attachments'],
            date: chatMsg['date'],
            msg_id: chatMsg['message_id']
        }
    }
}

And I need to place the value from chatMsg['message_id'] instead of the key name "msg".
Approximately like this:

var object = {
    _id: chatMsg['user_id'],
    chatlog: {
        chatMsg['message_id']: {
            attachments: chatMsg['attachments'],
            date: chatMsg['date']
        }
    }
}

When I try to do what I need, the node swears at a syntax error. It is clear.
How would you recommend solving the problem?

Answer 1

var object = {
    _id: chatMsg['user_id'],
    chatlog: {
        [chatMsg['message_id']]: {
            attachments: chatMsg['attachments'],
            date: chatMsg['date']
        }
    }
}

And this is not PHP here, arrays are different with us.