Why should you always write "varchar" with the length in brackets behind it? Often, you get the right outcome without doing so

"Often, you get the right outcome without doing so." Example: select CONVERT(varchar, getdate(), 112) outputs 20240417 I saw this in quite a few places on Stack Exchange until I found a tiny remark that told the reader not to forget the length in brackets. I claimed that this is not needed if you set the style number for a datetime like this. Yet, I got enough insight now to understand that "varchar should never stand alone", it should always be written as something like varchar(1234). As for the code above, that would be: select CONVERT(varchar(8), getdate(), 112) If you look at it, the output is the same: 20240417 Why should you still always write varchar with the length in brackets behind it? #### PS: If you can, take even char(8) instead of varchar(8) / nvarchar(8) A remark below went even further: char(8) should be taken since: > no value in style 112 will ever be less than 8 characters. #### Links that bring up this question This is just a random list of some links where I saw varchar() without brackets. There are many more out there. - [Convert date yyyy-mm-dd to integer YYYYMM - DBA SE](https://dba.stackexchange.com/a/106900/212659) - [SQL Server Convert Varchar to Datetime - Stack Overflow](https://stackoverflow.com/a/10247180/11154841) - [Convert date to number data type - Stack Overflow](https://stackoverflow.com/a/63625407/11154841) - [How to get a date in YYYY-MM-DD format from a TSQL datetime field?](https://stackoverflow.com/q/889629/11154841) - [Convert date to YYYYMM format](https://stackoverflow.com/a/14217859/11154841) - [SQL - The conversion of a varchar data type to a datetime data type resulted in an out-of-range value](https://stackoverflow.com/a/20840132/11154841)