String vs StringBuilder in C#

This explains the difference between System.String and System.Text.StringBuilder

When we wanted to work with text in C#, normally we use String DataType to store the values.

Ex:
String str;
str = “EggHeadCafe”;

But, when we wanted to manipulate the value assigned to the str variable in later stages, we simple do something like this:

str = str + “ is the best .Net forum”;

everythings looks fine, and no issues.

But, one should understand what really happens doing so. Once any string value is manipulated, it creates a new  object in the memory and does not re-use the same memory space allocated initially as String types in .Net are immutable.

The alternative to address this is using of StringBuilder which is mutable type in .Net

Ex:
StringBuilder str = new StringBuilder();
            str.Append("EggHeadCafe");
            str.Append(" is best .Net forum");

             MessageBox.Show(str.ToString());

Conclusion: Always use SrtringBuilder when you have to change the values of the string types instead of string as this is the efficient coding standard.