Java charAt used with characters that have two code units

Question

From Core Java, vol. 1, 9th ed., p. 69:

The character ℤ requires two code units in the UTF-16 encoding. Calling

String sentence =         


        

Answer 1

According to the documentation String is represented internally as utf-16, so charAt() is giving you two code points. If you are interested in seeing the individual code points you can use this code (from this answer):

final int length = sentence.length();
for (int offset = 0; offset < length; ) {
   final int codepoint = sentence.codePointAt(offset);

   // do something with the codepoint

   offset += Character.charCount(codepoint);
}