My question is this: Is string concatenation in C# safe? If string concatenation leads to unexpected errors, and replacing that string concatenation by using StringBuilder causes those errors to disappear, what might that indicate?
Background: I am developing a small command line C# application. It takes command line arguments, performs a slightly complicated SQL query, and outputs about 1300 rows of data into a formatted XML file.
My initial program would always run fine in debug mode. However, in release mode it would get to about the 750th SQL result, and then die with an error. The error was that a certain column of data could not be read, even through the Read() method of the SqlDataReader object had just returned true.
This problem was fixed by using StringBuilder for all operations in the code, where previously there had been “string1 + string2”. I’m not talking about string concatenation inside the SQL query loop, where StringBuilder was already in use. I’m talking about simple concatenations between two or three short string variables earlier in the code.
I had the impression that C# was smart enough to handle the memory management for adding a few strings together. Am I wrong? Or does this indicate some other sort of code problem?
Apart from what you’re doing is probably best done with XML APIs instead of strings or StringBuilder I doubt that the error you see is due to string concatenation. Maybe switching to StringBuilder just masked the error or went over it gracefully, but I doubt using strings really was the cause.