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

The real takeaway here should be a sequence should almost never be null in the first place. Simply make it an invariant in all of your programs that if you have a sequence, it is never null. It is always initialized to be the empty sequence or some other genuine sequence.

If a sequence is never null then obviously you don't need to check it.