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
Brian Patrick
Courses Plus Student 2,770 PointsWhen designating propTypes why do we include a coma at the end of the object if there is only one key?
For example: Application.propTypes = { title: React.PropTypes.string, };
2 Answers
Andrew Hickman
Full Stack JavaScript Techdegree Student 10,013 PointsHey Brian! It's not necessary to type a trailing comma. It's just become conventional, because it's easier to reorder properties and debug if you don't have to worry about you or someone else leaving that comma out. Whatever floats your boat. Do whatever is more convenient for you.
Robert Schaap
19,836 PointsLike Andrew mentioned, it isn't necessary but another good reason is when you're using git and someone else is reviewing changes you made to the code in a project.
If your line already ended with a comma and you hit enter to insert a new line, the reviewer will see only 1 change: the line you added. If you also added a comma on the line above, that line will also be shown as changed, though technically it didn't. In bigger files many small changes like that make it hard for a reviewer to see what actually changed and what's just spacing/commas etc.