How to be sure that message via socket.io has been received to the client?

Question

How to check that message sent with socket.io library has been received to the client. Is there special method for it in socket.io?

Thanks for you

Answer 1

When you add a function as the last parameter of .send() or .emit() method calls, this function is called when the other party receives the message.

socket.send('hi', function() {
    // if we are here, our salutation has been received by the other party.
});