C# equivalent of the vb isNothing
VB.Net IsNothing Function returns a Boolean value indicating whether an expression has no object assigned to it. There is no direct, 100% equivalent of the Vb.Net function IsNothing, but the test against null accomplishes the same thing.
IsNothing is intended to work on reference types. It returns True if the expression represents an object variable that currently has no object assigned to it; otherwise, it returns False.
The null keyword is specific design feature in the C# language. It is a literal that represents a null reference, one that does not refer to any object. null is the default value of reference-type variables