Are immutable arrays possible in .NET?

Question

Is it possible to somehow mark a System.Array as immutable. When put behind a public-get/private-set they can\'t be added to, since it requires re-allocation a

Answer 1

The Framework Design Guidelines suggest returning a copy of the Array. That way, consumers can't change items from the array.

// bad code
// could still do Path.InvalidPathChars[0] = 'A';
public sealed class Path {
   public static readonly char[] InvalidPathChars = 
      { '\"', '<', '>', '|' };
}

these are better:

public static ReadOnlyCollection GetInvalidPathChars(){
   return Array.AsReadOnly(InvalidPathChars);
}

public static char[] GetInvalidPathChars(){
   return (char[])InvalidPathChars.Clone();
}

The examples are straight from the book.