title: What is the C# equivalent of NSMutableArray and NSArray?
body: <p>What is the C# equivalent of <code>NSMutableArray</code> and <code>NSArray</code>?</p>
  
  <p>Does C# have a mutable and non-mutable? I noticed that <code>string</code> appears to be mutable by default.</p>
  
  <p>As a bonus, how do I quickly populate the array in C#?</p>