Unfortunately we don't have a String#codepoints or something that would return the number of code points as opposed to the number of characters (that "length" returns) - something like that imo would greatly simplify explaining the differences to people.
For the time being, I've been explaining that some characters are actually made up of two, and the 💩 character (it's a fun example to use) is an example of two characters combining to make one "code point". It's not a quick or trivial thing to explain but people do seem to grasp it eventually. On Wed, Apr 1, 2015 at 4:09 PM, Andrea Giammarchi < [email protected]> wrote: > and now I also gonna hope that `Array.from(foo).length // 2` wasn't by > accident, instead of `bar` ... > > On Thu, Apr 2, 2015 at 1:07 AM, Andrea Giammarchi < > [email protected]> wrote: > >> ```js >> foo.length; // 2 >> Array.from(foo).length // 1 >> >> bar.length; // 2 >> Array.from(bar).length // 2 >> ``` >> >> I know already everything you wrote ... now, how to explain to JS users >> out there and how to solve? >> >> On Thu, Apr 2, 2015 at 1:04 AM, Boris Zbarsky <[email protected]> wrote: >> >>> On 4/1/15 6:56 PM, Andrea Giammarchi wrote: >>> >>>> Why is that >>>> >>> >>> Because those are different things. The first is a single Unicode >>> character that happens to be represented by 2 UTF-16 code units. The >>> second is a pair of Unicode characters that are each represented by one >>> UTF-16 code unit, but also happen to form a single grapheme cluster >>> (because one of them is a combining character). To complicate things >>> further, there is also a single Unicode character that represents that same >>> grapheme cluster.... >>> >>> String length shows the number of UTF-16 code units. >>> >>> Array.from works on Unicode characters. That explains the foo.length >>> and Array.from(foo).length results. >>> >>> and how to solve? >>>> >>> >>> Can you clearly explain what problem you are trying to solve? >>> >>> -Boris >>> >>> _______________________________________________ >>> es-discuss mailing list >>> [email protected] >>> https://mail.mozilla.org/listinfo/es-discuss >>> >> >> > > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss > >
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