I tend to be a prolific user of semicolons in my JavaScript:
var x = 1;
var y = 2;
if (x==y){do something};
I recently noticed that I was looki
The habit comes from fear. Fear of "broken" js compressors (I've had some problems with Plone compressors with legacy js that didn't have the var
statement for example), fear of possible broken browser implementations, the list goes on. So, why not just use ;
everywhere and avoid all of these pitfalls?
The problem with this approach (just always use semicolons without further explanation) is that you don't try to understand why are you doing it in the first place, you just do because someone said you to do it, and, IMHO, this can be harmful as well. And the broken compressors you had in the past are now fixed, and you keep inserting semicolons... breaking habits is hard. We just keep doing things because "we always did it".
Many new JavaScript programmers are advised to just use semicolons everywhere, and expect that if they do not intentionally use the semicolon insertion rules, they can safely ignore the existence of this entire language feature. This is not the case, because of the restricted productions described above, notably the return statement. When becoming aware of the restricted production issue, programmers may then become overly wary of linebreaks, and avoid them even when they would increase clarity. It is best to be familiar with all the rules for ASI so as to be able to read any code regardless of how it is written, and to write code that is as clear as it can be.
Here is a great resource about this subject and the source of the quote. A great read.
So which style is better? To the extent that there is an objectively “better” choice, it appears to me that the minimal-semicolon/comma-first style is slightly superior, both because it is fundamentally more scannable and because it encourages programmers to better understand the language they use.
... and the 2nd quote from a more optionated article, against always using semicolons. A great read as well.