Text - UTF-16 Character Set
1 - About
UTF-16 is a variable-length encoding: Each code point in a UTF-16 encoding may require either one or two 16-bit code units. The size in memory of a string of length n varies based on the particular code points in the string.
Finding the nth code point of a string is no longer a constant-time operation as in ucs-2: It generally requires searching from the beginning of the string.