Is if(items != null) superfluous before foreach(T item in items)?

Question

I often come across code like the following:

if ( items != null)
{
   foreach(T item in items)
   {
        //...
   }
}

Basically, the

Answer 1

You can encapsulate the null check in an extension method and use a lambda:

public static class EnumerableExtensions {
  public static void ForEach(this IEnumerable self, Action action) {
    if (self != null) {
      foreach (var element in self) {
        action(element);
      }
    }
  }
}

The code becomes:

items.ForEach(item => { 
  ...
});

If can be even more concise if you want to just call a method that takes an item and returns void:

items.ForEach(MethodThatTakesAnItem);