Socket.io rooms difference between broadcast.to and sockets.in

Question

Socket.io\'s readme contains the following example:

    var io = require(\'socket.io\').listen(80);

    io.sockets.on         


        

Answer 1

Update 2019: socket.io is a special module which uses websockets and then fallsback to http request polling. For just websockets: for the client use native websockets and for node.js use ws or this library.

Simple example

The syntax is confusing in socketio. Also, every socket is automatically connected to their own room with the id socket.id (this is how private chat works in socketio, they use rooms).

Send to the sender and noone else

socket.emit('hello', msg);

Send to everyone including the sender(if the sender is in the room) in the room "my room"

io.to('my room').emit('hello', msg);

Send to everyone except the sender(if the sender is in the room) in the room "my room"

socket.broadcast.to('my room').emit('hello', msg);

Send to everyone in every room, including the sender

io.emit('hello', msg); // short version

io.sockets.emit('hello', msg);

Send to specific socket only (private chat)

socket.broadcast.to(otherSocket.id).emit('hello', msg);