title: Should updating an element in List<T> by index be quicker than using ArrayList index?
body: <p>I am running through some tests about using ArrayLists and List.</p>
  
  <p>Speed is very important in my app.</p>
  
  <p>I have tested creating 10000 records in each, finding an item by index and then updating that object for example:</p>
  
  <pre><code>List[i] = newX;
  </code></pre>
  
  <p>Using the arraylist seems much faster. Is that correct?</p>
  
  <p><strong>UPDATE:</strong> </p>
  
  <p>Using the List[i] approach, for my <code>List&lt;T&gt;</code> approach I am using LINQ to find the index eg/ </p>
  
  <p>....</p>
  
  <pre><code>int index = base.FindIndex(x=&gt;x.AlpaNumericString = "PopItem");
  base[index] = UpdatedItem;
  </code></pre>
  
  <p>It is definately slower than </p>
  
  <pre><code>ArrayList.IndexOf("PopItem"))
  base[index] = UpdatedItem;
  </code></pre>