@ULEN — Returns the number of Unicode characters in a string.

Syntax:
%@ULEN[string]

This functions is almost the same as @LEN, except that it counts properly-paired surrogates as a single character.

echo %@ulen[😺]

echo %@ulen[%@char[0xd83d 0xde00]]


Surrogates which are not properly paired will be counted as separate ‘characters’.