IsEmpty or IsNull or IsNothing?

Question

Can someone help me determine which I should be using?

Here is the situation - I am pulling a value from a column in the Data Table. If there is anything in that column, I set the data to a variable and take an action. If the column is blank, I want to skip that.

I am confused as to which IsWHATEVER statement would be best. For Example:

If IsEmpty(Datatable.Value("M4","Data_Entry"))=False Then

OR

If IsNull(Datatable.Value("M4","Data_Entry"))=False Then

OR

If IsNothing(Datatable.Value("M4","Data_Entry"))=False Then

Suggestions?

Solution

I've just tried all of your options and found this to be the most correct:

If (DataTable.Value("M4","Global") <> "") Then

Your original options will not work on QTP Datatables as these are for uninitialised objects or variables. However, in QTP as soon as you create a parameter in the Datatable the first value gets initialised as blank (not to be confused with empty).