string_length(s)
Return the number of characters in the string s.
By default string_length will return the number of bytes that make up the string:
string_length("hello, world")
// 12
string_length("您好世界")
// 12
If character input is set to a particular character encoding, string_length will count and
report the number of characters encoded into a string. For example, if the REPL is started with the
command line option
-:t8,-8, which set both the terminal and standard input to UTF-8 encoding, we get the following results:
string_length("hello, world")
// 12
string_length("您好世界")
// 4