I was looking at a support case recently where the value returned from a function was NULL when it was expected to contain a value. The puzzling thing was the change that led to the function returning NULL had occurred a few years ago and we were wondering why it had not been detected earlier. The reason it had not been detected was that a test to check the value did not consider the possibility that the value could be NULL.
In this article I show some strategies for coding expressions so that if a value is unexpectedly NULL your code will detect that the value is not as you expect, and take the right path through an IF ELSE.
Read more at
https://4js.com/ask-reuben/ig-87/
