Concrete JavaScript regular expression for accented characters (diacritics)

user_1986871 0
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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 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 = "àèìòùÀÈÌÒÙáéíóúýÁÉÍÓÚÝâêîôûÂÊÎÔÛãñõÃÑÕäëïöüÿÄËÏÖÜŸçÇßØøÅåÆæœ";
// Build the full regex
var regex = "^[a-zA-Z" + accentedCharacters + "]+,\\s[a-zA-Z" + accentedCharacters + "]+$";
// Create a RegExp from the string version
regexCompiled = new RegExp(regex);
// regexCompiled = /^[a-zA-ZàèìòùÀÈÌÒÙáéíóúýÁÉÍÓÚÝâêîôûÂÊÎÔÛãñõÃÑÕäëïöüÿÄËÏÖÜŸçÇßØøÅåÆæœ]+,\s[a-zA-ZàèìòùÀÈÌÒÙáéíóúýÁÉÍÓÚÝâêîôûÂÊÎÔÛãñõÃÑÕäëïöüÿÄËÏÖÜŸçÇßØøÅåÆæœ]+$/
  • This correctly matches a last/first name with any of the supported accented characters in accentedCharacters.

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...

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

/^[a-zA-Z\u00C0-\u017F]+,\s[a-zA-Z\u00C0-\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.

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

Which of these three approaches is most suited for the task? Or are there better solutions?

unicode javascript regex
10 Answers
/^[\pL\pM\p{Zs}.-]+$/u

Explanation:

  • \pL - matches any kind of letter from any language
  • \pM - matches a character intended to be combined with another character (e.g. accents, umlauts, enclosing boxes, etc.)
  • \p{Zs} - matches a whitespace character that is invisible, but does take up space
  • u - Pattern and subject strings are treated as UTF-8

Unlike other proposed regex (such as [A-Za-zÀ-ÖØ-öø-ÿ]), this will work with all language specific characters, e.g. Šš is matched by this rule, but not matched by others on this page.

Unfortunately, natively JavaScript does not support these classes. However, you can use xregexp, e.g.

const XRegExp = require('xregexp');

const isInputRealHumanName = (input: string): boolean => {
  return XRegExp('^[\\pL\\pM-]+ [\\pL\\pM-]+$', 'u').test(input);
};
user_3686910

You can use this:

^([a-zA-Z]|[à-ú]|[À-Ú])+$

It will match every word with accented characters or not.

user_48789100
user_24372240

My context is slightly different and limited to French: I want to search text by allowing a mistake of accents.

For example, I want to find "maîtrisée", but the text to be searched is "... maitrisee ...". So, I used the regular expression /ma[i|î|ï]tris[e|é|è|ê|ë]/ in JavaScript.

In the expression, the '[' and ']' define a set of characters, and the '|' is an OR condition.

This page gives a list of accented characters: Diacritiques utilisés en français

user_31423450
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