A Brief Note on Quotes

Quite a few languages allow strings to be put in either single (') or double (") quotes. Some of them – like PHP, Perl or Ruby – make a minor distinction by enabling string interpolation to occur only in doubly-quoted ones. Others – including Javascript and Python – offer no distinction whatsoever, bar the possible (in)convenience of using quote chars inside the strings themselves.

But if neither of those apply to your specific case, is there any compelling argument to prefer one type of quotes over another?…

Replying with “Who cares?” seems like a sane thing to do and until recently, I would have concurred. Indeed, it looks like a token example of something totally irrelevant. That’s why I was rather surprised to discover that there might be deep logic behind such choice.

And it’s pretty simple, really – almost obvious in hindsight. Use double quotes for strings which are to be eventually seen by user. Not necessarily the end-user, mind you; an admin or coder looking at logs is equally valid recipient. Similarly, reserve single quotes (apostrophes) for texts used internally: identifiers, enum-like values, keys within hashmaps, XML/JSON attributes, and the like.

It might still seem like somewhat superficial distinction – and blurry at times. But I think that ultimately, it pays off to focus a little on details such as these. As a benefit, we may develop a subtle sense of structure, allowing to see into underlying semantics that much quicker.