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JavaScript JavaScript and the DOM (Retiring) Responding to User Interaction Adding an Event Listener

Posted by Kinkaid Nolen
Kinkaid Nolen
4,859 Points

parameter vs listener

Is the second parameter and the listener(object that implements the Event) the same thing? Because I thought that "button" was the listener.

app.js 
var warning = document.getElementById("warning");
var button = document.getElementById('makeItRed');

button.addEventListener('click',button,warning,  );
index.html 
<!DOCTYPE html>
<html>
    <head>
        <title>Adding an Event Listener</title>
    </head>
    <link rel="stylesheet" href="style.css" />
    <body>
        <div id="warning">
            Warning: My background should be red!
        </div>
        <button id="makeItRed">Make It Red!</button>
        <script src="app.js"></script>
    </body>
</html>

1 Answer

Steven Parker
Steven Parker
231,269 Points
Steven Parker
Steven Parker
231,269 Points

The button is what is known as an "event target". The listener (or "event handler") is the code that will run when the event happens.

FYI, the "addEventListener" code shown above is not proper syntax. There should only be two arguments, and the second one should be listener (a function). For more details, see the MDN page on addEventListener.

Kinkaid Nolen
Kinkaid Nolen
4,859 Points

Thank you