io.sockets.emit code example

Example 1: socket emit to specific room using nodejs socket.io

io.on('connection', socket => {  socket.on('disconnecting', () => {    const rooms = Object.keys(socket.rooms);    // the rooms array contains at least the socket ID  });  socket.on('disconnect', () => {    // socket.rooms === {}  });});

Example 2: socket emit to specific room using nodejs socket.io

io.to('room1').to('room2').to('room3').emit('some event');