title: Replace string values in list
body: <p>I have a collection of strings which contain values like "goalXXvalue,goalXXLength,TestXX". It is a List(of String)
  I thought I would be able to loop through each item and replace the XX value which I've tried with the method below but the values don't change. Where am I going wrong?
  Thanks</p>
  
  <p><code>metricList.ForEach(Function(n) n.Replace("XX", "1"))
  </code></p>