[wutwutwat]

`””` vs `''` isn’t just a style rule. In Ruby there are performance implications with double quoted strings. Strings in double quotes are interpolated for variable substitution, whereas strings in single quotes are processed literally, no variable replacement overhead. Is it going to matter for most code? Probably not, but good to know nonetheless imo.

[tomstuart]

This sounds intuitively true, but it’s a (very persistent) myth: https://www.viget.com/articles/just-use-double-quoted-ruby-s...

[wutwutwat]

TIL. Thanks

[codesnik]

I also am not sure why it's intuitive at all. Article doesn't mention why - ruby has a parse phase, it doesn't scan your string byte for byte every time it runs looking for an interpolation. During the parse those "foo#{bar}" are replaced by something like 'foo'.dup << bar.to_str in the bytecode, but that happens only when parser hits #{ in a double quoted string, there's no penalty for that and it happens just once. Only really old, naive interpretators parse source code each time line is hit. (Or some weird ones, where interpolation can change semantics and argument count, like tcl and bash.)

[codesnik]

this isn't true for any half-ass interpretator out there. Perhaps some old PHP executable was slower with different quotes, but it's not true for ruby for decades. In bytecode there's zero distinction between "" and ''. Don't believe me? benchmark.