String.prototype.toLocaleUpperCase()
The toLocaleUpperCase()
method returns the calling string
value converted to upper case, according to any locale-specific case mappings.
Syntax
toLocaleUpperCase()
toLocaleUpperCase(locale)
toLocaleUpperCase([locale1, locale2, ...])
Parameters
locale
Optional-
The
locale
parameter indicates the locale to be used to convert to upper case according to any locale-specific case mappings. If multiple locales are given in anArray
, the best available locale is used. The default locale is the host environment's current locale.
Return value
A new string representing the calling string converted to upper case, according to any locale-specific case mappings.
Exceptions
-
A
RangeError
("invalid language tag: xx_yy") is thrown if alocale
argument isn't a valid language tag. -
A
TypeError
("invalid element in locales argument") is thrown if an array element isn't of type string.
Description
The toLocaleUpperCase()
method returns the value of the string converted
to upper case according to any locale-specific case mappings.
toLocaleUpperCase()
does not affect the value of the string itself. In most
cases, this will produce the same result as toUpperCase()
, but for some locales, such as Turkish, whose case mappings do not
follow the default case mappings in Unicode, there may be a different result.
Also notice that conversion is not necessarily a 1:1 character mapping, as some
characters might result in two (or even more) characters when transformed to upper-case.
Therefore the length of the result string can differ from the input length. This also
implies that the conversion is not stable, so i.E. the following can return
false
:
x.toLocaleLowerCase() === x.toLocaleUpperCase().toLocaleLowerCase()
Examples
Using toLocaleUpperCase()
'alphabet'.toLocaleUpperCase(); // 'ALPHABET'
'Gesäß'.toLocaleUpperCase(); // 'GESÄSS'
'i\u0307'.toLocaleUpperCase('lt-LT'); // 'I'
let locales = ['lt', 'LT', 'lt-LT', 'lt-u-co-phonebk', 'lt-x-lietuva'];
'i\u0307'.toLocaleUpperCase(locales); // 'I'
Specifications
Specification |
---|
ECMAScript Language Specification # sec-string.prototype.tolocaleuppercase |
ECMAScript Internationalization API Specification # sup-string.prototype.tolocaleuppercase |
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