[Negative1]

I don't believe its equivalent. When I'm writing Scala code in the backend and have to switch to frontend I often find myself omitting the semi-colons but going back and fixing due to self-imposed coding conventions. For Javascript just as in Python or Scala, semi-colons are optional for a good reason.

[bigtunacan]

We would all be better off if semi colons had just been required in JavaScript. The problem is that semi colons are not actually optional in JavaScript. Instead JavaScript use ASI, automatic semi colon invasion, where the compiler attempts to determine where semi colons should go. Unfortunately the rules are complex, prone to certain errors, and I can't rely on everyone I ever work with understanding all of those rules. For all of these reasons if you are writing JavaScript you should just use semi colons.

[tauchunfall]

>Unfortunately the rules are complex, prone to certain errors, and I can't rely on everyone I ever work with understanding all of those rules.

Are they really complex? This recently released version 4.0.0 of the JavaScript Standard Style [1] suggests to never start a line with "(" or "[". This rule looks even simpler than the rules of operator precedence.

[1] https://github.com/feross/standard

Update: Now I learned about the JavaScript Semi-Standard Style [2] which accually enforces semi-colons. Quite hilarious.

[2] https://github.com/Flet/semistandard

[bigtunacan]

They are complicated enough; and different enough from other languages that they lead to unexpected behaviors. It is just easier to say, "everyone must use semi-colons". Then I can add linting into our build process and reduce risk of bugs.

One quick example is the very contrived example that follows.

return {a:1, b:2}

That is valid JavaScript. It is evaluated as an empty return and an unreachable expression. Probably not what was intended.

I've sent copies of the rules to people and explained them numerous times, but at the end of the day it is more productive to just use them and move on to something else IMHO.

[rhaps0dy]

http://blog.izs.me/post/2353458699/an-open-letter-to-javascr...

Please stop spreading FUD.

[skue]

If you have an argument to make, then make it.

The previous poster didn't say he was unwilling to learn JS semicolon rules, he was saying he couldn't trust everyone he ever works with to learn them. Replying with an accusation of FUD and a link to someone ranting that it's unprofessional for JS devs to not know these rules is unnecessarily inflammatory while missing his point.

[raverbashing]

Well, semicolons may be optional in Python but the official python style strongly recommends agains (needing to use them)

It's not about forgetting them once in a while, it's about playing a game of "needs a semicolon or doesn't" which increases the (already high) number of things the developer needs to worry about

[netheril96]

In Python you usually don't add semi-colons, and it will bark when your intention is unclear.

In javascript you may omit semicolons, but the interpreter will guess your intention when it is ambiguous and it will probably guess it wrong.