Issue With REPLICATE and Strings in SQL Server 2008 - sql-server

Question

One of the functions of our app is that it prints out "sales tapes" that help the tellers close each night. These tapes print on a 40-character, fixed-width heat-paper printer. At the moment these use deprecated code to load the data from our sales tables instead of the reporting "cube" tables. I'm rewriting them to use the cubes.
I'm running into an issue formatting the text in SQL Server 2008. I'm using the REPLICATE function to calculate out each side of the columns, per line. For some reason some of the lines just randomly have an extra character and are 41 characters in width. Needless to say, that prevents amounts from properly appearing. The two columns are 27 characters and 13 characters
Here is an example. Below is are the pieces. From left to right: left spaces, length of left column text, right spaces, length of right column text. | 40 shows that the total of everything is 40 characters
20 7 7 6 | 40
18 9 3 10 | 40
7 20 13 0 | 40
In this case, the left text is 7 characters, followed by 20 spaces, followed by 7 spaces, followed by 6 characters, all of which would be 40 total characters. What it should read is this (account masked for safety):
STEWART $57.70
AT&T (DP) Fee: $1.50
Acct: xxxxxxxxxxxxxx
However, what it actually reads is:
STEWART $57.7
AT&T (DP) Fee: $1.50
Acct: xxxxxxxxxxxxxx
I can't figure out why it is including too many spaces. If you compare, you can see that $57.70 is 6 characters, as calculated in the first line. Yet it appears as 5 because it is truncated by the 20 + 7. Some how 20 (left spaces) + 7 (left text) + 7 (right spaces) + 6 (right text) is equaling 41!! Below is my code in the UDF:
DECLARE #ReturnValue NVARCHAR(40) = '';
DECLARE #LeftSpaces INT = #LeftSideWidth;
DECLARE #RightSpaces INT = (#PageWidth - #LeftSideWidth);
--remove header text space
SET #LeftSpaces = #LeftSpaces - LEN(#LeftText);
SET #RightSpaces = #RightSpaces - LEN(#RightText);
SET #ReturnValue = #LeftText; --add our left column
SET #ReturnValue = #ReturnValue + REPLICATE(' ', #LeftSpaces); --add our left spaces
SET #ReturnValue = #ReturnValue + REPLICATE(' ', #RightSpaces); --add our right spaces
SET #ReturnValue = #ReturnValue + #RightText; --finally, add our right text;
RETURN #ReturnValue;
The UDF is pretty simple. First, I set the spaces to equal the full length of both columns. Then I reduce the count of spaces by the length of the text to appear in the column on this line. Then I add the left text, left spaces, right spaces, and finally the right-aligned text together and return it. For most rows it works perfect. For random rows (so far those with 6, 7, and 15 length on left text), I get what appeared above. The UDF was written to be more succinct originally but I finally broke it out logically into steps when I couldn't figure out what was wrong.
Anyone have an idea? Where is my math wrong?

Answer 1

try using the LEFT and RIGHT functions along with REPLICATE, like so:
DECLARE #ReturnValue NVARCHAR(40) = '';
DECLARE #LeftSpaces INT = #LeftSideWidth;
DECLARE #RightSpaces INT = (#PageWidth - #LeftSideWidth);
--remove header text space
SET #LeftSpaces = #LeftSpaces - LEN(#LeftText);
SET #RightSpaces = #RightSpaces - LEN(#RightText);
SET #ReturnValue = LEFT(#LeftText + REPLICATE(' ', #LeftSpaces), #LeftSideWidth); --add our left column
SET #ReturnValue = #ReturnValue + RIGHT(REPLICATE(' ', #RightSpaces) + #RightText, (#PageWidth - #LeftSideWidth)); --finally, add our right text;
RETURN #ReturnValue;