It’s Not Wrong that "🤦🏼♂️".length == 7 But It’s Better that "🤦🏼♂️".len() == 17 and Rather Useless that len("🤦🏼♂️") == 5
From time to time, someone shows that in JavaScript the .length of a string containing an emoji results in a number greater than 1 (typically 2) and then proceeds to the conclusion that haha JavaScript is so broken—and is rewarded with many likes. In this post, I will try to convince you that ridiculing JavaScript for this is less insightful than it first appears and that Swift’s approach to string length isn’t unambiguously the best one. Python 3’s approach is unambiguously the worst one, though.
What’s Going on with the Title?
"🤦🏼♂️".length == 7 evaluates to true as JavaScript. Let’s try JavaScript console in Firefox:
"🤦🏼♂️".length == 7 true
Haha, right? Well, you’ve been told that the Python community suffered the Python 2 vs. Python 3 split, among other things, to Get Unicode Right. Let’s try Python 3:
$ python3 Python 3.6.8 (default, Jan 14 2019, 11:02:34) [GCC 8.0.1 20180414 (experimental) [trunk revision 259383]] on linux Type "help", "copyright", "credits" or "license" for more information. >>> len("🤦🏼♂️") == 5 True >>>
OK, then. Now, Rust has the benefit of learning from languages that came before it. Let’s try Rust:
$ cargo new -q length $ cd length $ echo 'fn main() { println!("{}", "🤦🏼♂️".len() == 17); }' > src/main.rs $ cargo run -q true
That’s better!
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