Does Javascript string.toLowerCase() follow Unicode standards in case-conversions?

Question

I'm creating a browser-based form verification script that checks if the input doesn't have any uppercase characters according to Unicode Standards. My definition of an uppercase character is a character that has a lowercase mapping. If a certain character in the input string doesn't have a lowercase or uppercase mapping (like chinese characters) then it's alright (it should pass my validation).

I'm using UTF-8 encoding.

I'm planning to create a function that looks like this:

function hasUpper(str){
  if(str != str.toLowerCase()){
    return true
  }
  else {
    return false
  }
}

Will this work for my needs?

Thanks!

Note that you can simplify that function to return str != str.toLowerCase(). — Eli Grey
– Eli Grey, Commented Aug 28, 2010 at 16:31

Robusto · Accepted Answer · 2010-08-28 13:07:25Z

11

Yes, that will work. Incidentally, the Boolean keywords are true and false, lower case. :)

answered Aug 28, 2010 at 13:07

Robusto

32k8 gold badges59 silver badges79 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

HBP Over a year ago

I the same vein the function can be shortened to: function hasUpper (str) { return str !== str.toLowerCase (); } Bah, no formatting in comments :-(

Robusto Over a year ago

@Hans B PUFAL: asddYou can format by bracketing with the backwards accent character, which is the lowercase option on the tilde key (~).

Nico Burns Over a year ago

not neccesarily - im the # symbol is the lowercase option on my (UK) keyboard. The backtick symbol is above the tab key.

Robusto Over a year ago

@Nico Burns: Reminds me of Shaw's comment that England and America are two countries separated by a common language. Cheers. :)

Albert Over a year ago

Thanks! the Boolean keywords are in lowercase, indeed.

Community · Accepted Answer · 2017-05-23 11:33:13Z

3

The question answered here seems to indicate that toLower and toUpper are Unicode-aware:Stack OverFlow

And this one goes into it in more detail (indicating that some mappings conflict with the real world):more Stack Overflow

Hope this helps!

edited May 23, 2017 at 11:33

CommunityBot

11 silver badge

answered Aug 28, 2010 at 13:09

A. Wilson

8,8791 gold badge29 silver badges40 bronze badges

Collectives™ on Stack Overflow

Does Javascript string.toLowerCase() follow Unicode standards in case-conversions?

2 Answers 2

5 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

5 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related