String.fromCharCode constructor
Allocates a new String for the specified charCode.
If the charCode can be represented by a single UTF-16 code unit, the new
string contains a single code unit. Otherwise, the length is 2 and
the code units form a surrogate pair. See documentation for
fromCharCodes.
Creating a String with half of a surrogate pair is allowed.
Implementation
external factory String.fromCharCode(int charCode);