Best way to remove the last character from a string built with stringbuilder

Question

I have the following

data.AppendFormat(\"{0},\",dataToAppend);

The problem with this is that I am using it in a loop and there will be a t

Answer 1

Gotcha!!

Most of the answers on this thread won't work if you use AppendLine like below:

var builder = new StringBuilder();
builder.AppendLine("One,");
builder.Length--; // Won't work
Console.Write(builder.ToString());

builder = new StringBuilder();
builder.AppendLine("One,");
builder.Length += -1; // Won't work
Console.Write(builder.ToString());

builder = new StringBuilder();
builder.AppendLine("One,");
Console.Write(builder.TrimEnd(',')); // Won't work

Fiddle Me

WHY??? @(&**(&@!!

The issue is simple but took me a while to figure it out: Because there are 2 more invisible characters at the end CR and LF (Carriage Return and Line Feed). Therefore, you need to take away 3 last characters:

var builder = new StringBuilder();
builder.AppendLine("One,");
builder.Length -= 3; // This will work
Console.WriteLine(builder.ToString());

In Conclusion

Use Length-- or Length -= 1 if the last method you called was Append. Use Length =- 3 if you the last method you called AppendLine.