Substring/Top and tail: Difference between revisions

I solve this problem two ways. First I use substring which is relatively fast for small strings, since it simply grabs the characters within a set of given bounds. The second uses regular expressions, which have a higher overhead for such short strings, but work correctly with all Unicode code points, not just those in the Basic Multilingual Plane.

Nearly all current solutions for this task fail to work correctly: the task says "The program must reference logical characters (code points), not 8-bit code units for UTF-8 or 16-bit code units for UTF-16." The abovecode program, as most on this page,below works onlycorrectly with all Unicode codecharacters, pointswithout inusing theregular Basicexpressions Multilingual Plane. The code below, onas the otherabove hand,program works correctly with all Unicode charactersdoes.