Is object valid handle class object
Hl = isvalid(Hobj)
Hl = isvalid(Hobj) returns a logical array (or scalar if Hobj is scalar) in which each element is true if the corresponding element in Hobj is a valid handle. This method is Sealed, so you cannot override it in a handle subclass.
Note: This method does not work with Handle Graphics® objects. To determine the validity of a Handle Graphics object handle, use the ishghandle function.