strlength counts the number of code
units in a string. Code units are bit sequences for encoding
characters of a character encoding system. In some character encodings,
such as UTF-16, there are some characters that are encoded with multiple
code units.
If you have a string or a character vector that contains such
characters, then the number of code units is greater than the number
of characters.
length(C) also returns the number of code
units when C is a character vector.