Question

I am building up a string of data using substring. The format of the data I want is

[1,2,3,4,5,6,7,8,9,10]

So I am building it up as follows

StringBuilder sb = new StringBuilder();
sb.append("1,");
sb.append("2,");
sb.append("3,");
.
.
.

The problem I run into is when I want to trim the final , before adding the closing ].

I could do

sb.ToString();
sb.Substring(0, (sb.Length - 1));
sb += "]";

But using the += is not very efficient as this creates a new string. Is there a better way of doing this?

Answer 1

The easiest is to use -= on the StringBuilder‘s Length since it’s writable:

sb.Length -= 1; // removes the last char