Ben Myhre
28,726 PointsAre commas at the last key pairs standard practice? That feels ugly
In the video, he has
Application.propTypes = {
title: React.PropTypes.string,
};
Application.defaultProps = {
title: "Scoreboard",
}
I feel like that last should not have a comma. It works, but I wonder what best practice is
2 Answers
Jennifer Nordell
Treehouse TeacherHi there! I've seen this question before and some languages simply don't allow it. However, I've also seen this done in PHP. The idea here is that when you are coding and wanting to add new properties quickly, it happens (often enough) that you forget to put a comma on the previous line and start writing the next property. This, of course, results in a syntax error. I have seen several instructors do this on Treehouse and I've even seen it a bit out in the wild (though I'd be hard pressed to say exactly where).
Hope this helps!
Adam Fields
Full Stack JavaScript Techdegree Graduate 37,809 PointsIt's a rule in the Airbnb Style Guide, and Jim works at Airbnb, so I'm guessing he's following the guide used at his company.
FWIW, I've seen Facebook React devs use this to, but I still can't get on the bandwagon. Feels weird.
Here's the ESLint rule: http://eslint.org/docs/rules/comma-dangle
And here is an article on why it's become en vogue: https://medium.com/@nikgraf/why-you-should-enforce-dangling-commas-for-multiline-statements-d034c98e36f8
Ben Myhre
28,726 PointsI think about it and it actually makes sense. It is consistent. That being said, it still feels weird to me.