Got to know that by default it takes the length as 1 if the size is not declared. Thank you....

However, I still did not get the difference between length of normal declaration and Cast/Convert... Please find below the queries....

1) SELECT

LEN('xyz') AS 'Declared'

, LEN(CONVERT(VARCHAR,'xyz')) AS 'Converted'

, LEN(CAST('xyz' AS VARCHAR)) AS 'Cast'

Ans : 3,3,3

2)

DECLARE @a VARCHAR ='xyz'

SELECT

LEN(@a) AS 'Declared'

, LEN(CONVERT(VARCHAR,@a)) AS 'Converted'

, LEN(CAST(@a AS VARCHAR)) AS 'Cast'

Ans : 1,1,1

I did not get default of 30 (which you mentioned in the answer in case of Cast/Convert) in what ever way I try... Can you please explain more on this?