string.Replace (or other string modification) not working

Question

For the following code, I can\'t get the string.Replace to work:

someTestString.Replace(someID.ToString(), sessionID);

when I

Answer 1

You can achieve the desired effect by using

someTestString = someTestString.Replace(someID.ToString(), sessionID);

As womp said, strings are immutable, which means their values cannot be changed without changing the entire object.