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

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

that should work for you

Answer 2

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.

Answer 3

Strings are immutable. The result of string.Replace is a new string with the replaced value.

You can either store result in new variable:

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

or just reassign to original variable if you just want observe "string updated" behavior:

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

Note that this applies to all other string functions like Remove, Insert, trim and substring variants - all of them return new string as original string can't be modified.

Answer 4

strings are immutable, the replace will return a new string so you need something like

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