Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

JavaScript Callback Functions in JavaScript Introduction to Callback Functions Using a Function as a Callback

Kevin Lewis
seal-mask
.a{fill-rule:evenodd;}techdegree
Kevin Lewis
Front End Web Development Techdegree Student 9,667 Points
Posted by Kevin Lewis
.a{fill-rule:evenodd;}techdegree
Kevin Lewis
Front End Web Development Techdegree Student 9,667 Points

Help Creating an Anonymous Callback Function

Keep getting either a syntax error or that the log didn’t go through the functionRunner. Help would be appreciated,

app.js 
function log() {
  console.log("Hello World!");
}

functionRunner(log);



functionRunner(function() {
  console.log("Hello World!");
})
index.html 
<!DOCTYPE html>
<html lang="en">
    <head>
        <title></title>
        <link rel='stylesheet' href='styles.css'>
    </head>
    <body>
        <section>
            <p>Open your browser's console to see the results</p>
        </section>
        <script src='runner.js'></script>
        <script src='app.js'></script>
    </body>
</html>
runner.js 
function functionRunner(callback) { 
  callback();
}

1 Answer

Dylan Glover
Dylan Glover
2,537 Points
Dylan Glover
Dylan Glover
2,537 Points

Pretty sure this is all you need in your app.js to callback the log as an anonymous function:

functionRunner(function () {
  console.log("Hello World!");
});

Hope that helps, Dylan