Comment by snek

I see a lot of comments here suggesting that == is okay to use if you know what you're doing or if the types on both sides match or if this or if that. Writing idiomatic code is all about being expressive and being explicit. Even in the most common case, testing for null or undefined, it's absolutely not clear what is actually happening or what the intent is. I write a lot of JS, and I've never had any justifiable reason to use ==.