What is the difference between 'foo = Nothing' and 'foo is Nothing' in VB.NET?

Question

In VB.NET, what is the difference between

if foo is Nothing Then
      doStuff()
End If

and

if foo=Nothing Then
    doStuff         


        

Answer 1

foo is Nothing simply checks if `foo` is not assigned to any reference.

foo=Nothing checks if the reference held by `foo` is equal to `nothing`

In VB, both statements will evaluate to the same value if foo has not been initialised