Given 2 columns (A,B), how to filter column B based on values in column A?

Question

I have an excel spreadsheet that looks similar to the table below:

A	B
Null	Null
Null	Null
To	John Doe
CC	Jane Doe
To	Null
CC	Null

I want to filter the table so that rows that have a value in A but Null in B do not show, similar to table below:

A	B
Null	Null
Null	Null
To	John Doe
CC	Jane Doe

Answer 1

Use:

=FILTER(A1:B6,NOT((A1:A6<>"Null")*(B1:B6="Null")))