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javastringunicodelocalecase-sensitive

Purpose of String.toLowerCase() with default locale?

Java has two overloads each for String.toLowerCase and toUpperCase. One of the overloads takes a Locale as a parameter while the other one takes no parameters and uses the default locale (Locale.getDefault()).

The parameterless variants might not work as expected because case conversion respects internationalization, and the default locale is system dependent. Most notably, the lower case i is converted to an upper case dotted İ in the Turkish locale.

What is the purpose of these methods? Do the parameterless variants have any legitimate use? Or perhaps they were just a design mistake? (Not unlike several I/O APIs that use the system default character encoding by default.)

Solution

  • Several blog posts suggest that default locales and charsets indeed were a design mistake and have no meaningful use.