Concrete Javascript Regex for Accented Characters (Diacritics)

Question

I've looked on Stack Overflow (replacing characters.. eh, how JavaScript doesn't follow the Unicode standard concerning RegExp, etc.) and haven't really found a concrete answer to the question:

How can JavaScript match for accented characters (those with diacritical marks)?

I'm forcing a field in a UI to match the format: last_name, first_name (last [comma space] first), and I want to provide support for diacritics, but evidently in JavaScript it's a bit more difficult than other languages/platforms.

This was my original version, until I wanted to add diacritic support:

/^[a-zA-Z]+,s[a-zA-Z]+$/

Currently I'm debating one of three methods to add support, all of which I have tested and work (at least to some extent, I don't really know what the "extent" is of the second approach). Here they are:

Explicitly listing all accented characters that I would want to accept as valid (lame and overly-complicated):

---

var accentedCharacters = "àèìòùàèìòùáéíóúyáéíóúYaê????ê?????????????ü?????ü???????????";
// Build the full regex
var regex = "^[a-zA-Z" + accentedCharacters + "]+,\s[a-zA-Z" + accentedCharacters + "]+$";
// Create a RegExp from the string version
regexCompiled = new RegExp(regex);
// regexCompiled = /^[a-zA-ZàèìòùàèìòùáéíóúyáéíóúYaê????ê?????????????ü?????ü???????????]+,s[a-zA-ZàèìòùàèìòùáéíóúyáéíóúYaê????ê?????????????ü?????ü???????????]+$/

• This correctly matches a last/first name with any of the supported accented characters in accentedCharacters.

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My other approach was to use the . character class, to have a simpler expression:

var regex = /^.+,s.+$/;

• This would match for just about anything, at least in the form of: something, something. That's alright I suppose...

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The last approach, which I just found might be simpler...

/^[a-zA-Zu00C0-u017F]+,s[a-zA-Zu00C0-u017F]+$/

• It matches a range of unicode characters - tested and working, though I didn't try anything crazy, just the normal stuff I see in our language department for faculty member names.

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Here are my concerns:

1. The first solution is far too limiting, and sloppy and convoluted at that. It would need to be changed if I forgot a character or two, and that's just not very practical.
2. The second solution is better, concise, but it probably matches far more than it actually should. I couldn't find any real documentation on exactly what . matches, just the generalization of "any character except the newline character" (from a table on the MDN).

3. The third solution seems the be the most precise, but are there any gotchas? I'm not very familiar with Unicode, at least in practice, but looking at a code table/continuation of that table, u00C0-u017F seems to be pretty solid, at least for my expected input.

   • Faculty won't be submitting forms with their names in their native language (e.g., Arabic, Chinese, Japanese, etc.) so I don't have to worry about out-of-Latin-character-set characters

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So the real question(s): Which of these three approaches is most suited for the task? Or are there better solutions?

question from:https://stackoverflow.com/questions/65853036/regex-match-any-word-followed-by-a-number-but-the-word-can-contain-special-char

Answer 1

The easier way to accept all accents is this:

[A-zà-ú] // accepts lowercase and uppercase characters
[A-zà-?] // as above but including letters with an umlaut (includes [ ] ^  × ÷)
[A-Za-zà-?] // as above but not including [ ] ^ 
[A-Za-zà-??-??-?] // as above but not including [ ] ^  × ÷

See https://unicode-table.com/en/ for characters listed in numeric order.