What is the difference between len() and DATALENGTH. I tried both in a SELECT, both are returning the same value. Can someone give me an example?

DATALENGTH returns the length of the string in bytes, including trailing spaces. LEN returns the length in characters, excluding trailing spaces. For example,


SELECT
LEN('string'),
LEN('string '),
DATALENGTH('string'),
DATALENGTH('string '),
LEN(N'string'),
LEN(N'string '),
DATALENGTH(N'string'),
DATALENGTH(N'string ')


will return 6, 6, 6, 9, 6, 6, 12, 18