JavaScript Error: Uncaught TypeError: foo is not a function

Question

For some reason JavaScript doesn\'t seem to recognise my function.

I have a button in some HTML:

Answer 1

Try this:

var lightOn = function(){

}

And you can do all of this in vanilla JS instead of using jQuery too:

var lightOn = function(){
    document.getElementById('lightOn').className += " active";
    document.getElementById('lightOff').className.replace(/\bactive\b/,'');
    socket.emit("setting", {"light":"on"});
}

A good explanation for var lightOn = function() and function lightOn() can be found here: https://stackoverflow.com/a/336868/1887101