SocketIO Data Undefined

I'm trying to send data from my client to my server side. I only get undefined. I would like the user to click the ledOn function to send 1 and also click the ledOff to send 0 to

Solution 1:

Change client.js to emit some data in the case of an "ON" or "OFF" event. For example, below, I am sending a "1" and "0" in ledOn() and ledOff() respectively.

function ledOn() {
    socket.emit ('ON', "1");
    document.getElementById("ON").value = "1"
    console.log("LED is on");
 }

 function ledOff() {
    socket.emit('OFF', "0");
    document.getElementById("OFF").value = "0"
    console.log("LED is off");
 }

Check out the Socket.IO docs to see some of their examples.