When and best way to make exact copies of strings in C#

Question

Let's say I have an array of strings from executing this Split method

string[] parsed = message.Split(' ');

And then I want to store a certain value of this array in a new string

string name = parsed[3];

Now I remove this string from the array using an extension method, this method removes the value at the specified index and shifts everything back to fill the gap

parsed = parsed.RemoveAt(3);

I am aware that because strings are reference types in C# my name variable is now null, after searching a little I've been told that making exact copies of strings in C# is useless. What is the best and correct way to set the name variable as a new instance so that it does not get deleted after the .RemoveAt() call?

EDIT:

This is the best way that I found so far

string name = new string(parsed[3].ToCharArray());

Another way proposed by Willy David Jr

parsed = parsed.Where((source, index) => index != 3).ToArray();

EDIT 2:

Please disregard this question and read the approved answer, I misunderstood how reference types work.

Answer 1

You're misunderstanding how reference types work. Removing an object from an array does not modify that object in any way - it just means that the array no longer contains a reference to the object.

You can test this yourself. Run the code you included in the debugger (or a console app) and then view (or print out) the value of name at the end.

The thing that can trick you up with reference types occurs when there are two variables (or arrays or whatever) that hold a reference to the same object. In this case, changes made to the object via one variable will be reflected when the object is accessed via another variable - it's the same object, but with two different variables referencing it. If you want both variables to refer to their own "copy" of the object, you have to create a copy yourself and assign it to one of the variables.

However, in C#, the string type is immutable, meaning that once a string object is created there is no way to change that object. So there is never a reason to create a copy of a string. If there is a variable that references a particular string, you can be sure that no other reference can change it out from under you.

Answer 2

Are you sure that there is RemoveAt at your string? There is RemoveAt on Collections but not on string or string array per se.

You can do this instead:

 List<string> lstParse = new List<string>();

 foreach (var i in parsed)
    {
       lstParse.Add(i);
    }
 string name = parsed[3];      
 lstParse.RemoveAt(3);

To join again the list and convert it to string:

string strResult = string.Join(" ", lstParse.ToArray());

If you really want to remove index without a new list of object, disregard the code above and you can do this one line instead:

 parsed = parsed.Where((source, index) => index != 3).ToArray();

Answer 3

Why do you think your name variable should be null? It will stay untouched after removal from array. Your original code is enough to accomplish what you desire.