Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

JavaScript Asynchronous Programming with JavaScript Asynchronous JavaScript with Callbacks Callbacks Review

J Tan
J Tan
11,847 Points

If a function is called from another function but is not passed in as a callback, is the parent function asynchronous?

If a function is called from another function but is not passed in as a callback, is the parent function asynchronous? Are callbacks a prerequisite for asynchronous functions?

1 Answer

Steven Parker
Steven Parker
210,425 Points

While callbacks are a common communication method for asynchronous functions, just having one does not make a function asynchronous. Plus you can have asynchronous functions that don't take callbacks (example: "fetch").

And simply calling a (normal) function from inside another one does not make either one asynchronous.

J Tan
J Tan
11,847 Points

What is the benefit of using callbacks vs calling another function within the body of the parent function? Is it for readability because the callback is listed as one of the function arguments?

Steven Parker
Steven Parker
210,425 Points

A function called in the body will always be the same function. But with a callback, the caller tells the function which other function to call, so it might be different each time.