string.usub(str, startpos, endpos)
or
str:usub(startpos, endpos)
This routine returns a substring of str. It is the Unicode version of string.sub. It accounts for multi-byte characters encoded in UTF-8.
Caution
This is an expensive routine. It allocates a temporary memory buffer during its operation.
Listing 15.1: Examples for string.usub()
print(string.usub("abc", 1, 1)) -- prints "a"
print(string.usub("abc", 2, 2)) -- prints "b"
print(string.usub("abc", 2, 3)) -- prints "bc"
Introduced in platform.apiLevel = '1.0'