node.js socket.io How to emit to a particular client?

Question

I want to \"emit\" a message to a particular client which is selected based on another message received in a different client, How do I do this?

I am thinking of joinin

Answer 1

Emitting to a particular client using a socketID.

Server/ package: socket.io:

io.to(socketID).emit('testEvent', 'yourMessage');

Client/ package socket.io-client:

io.sockets.on('connection',(socket) => {
  socket.on("testEvent", data => {
    console.log(data);
  });
});

You can get access the socketID in the following manner:

io.on('connection', (socket, next) => {
    const ID = socket.id // id property on the socket Object
})

It is simply a property on the socket object