>> In Java a string is a class, objects of which contain sequence of
>> characters, a character is a 16-bit value that can be casted to int.
>> They are UTF-16.
>
> How can char always be 16-bit if it is UTF-16 not UCS-2 ?

"Java originally used UCS-2, and added UTF-16 supplementary character
support in J2SE 5.0. However, non-BMP characters require the individual
surrogate halves to be entered individually, for example: "\uD834\uDD1E"
for U+1D11E.[14]"

http://en.wikipedia.org/wiki/UTF-16

Roman