Comment by inopinatus

The more experienced a developer I become, the more strongly (and negatively) I feel about nils and nulls and their ilk. I have sympathy for C.A.R.Hoare who in 2009 apologised for the apparent invention of null references in ALGOL W (1965), calling them a "billion-dollar mistake". I've come to regard them as a data singularity, and when I design data structures and interfaces today I am deliberately avoiding/outlawing them; all my relational fields are NOT NULL and I choose either meaningful defaults, or EAV or equivalents instead; in method parameters I would rather something not exist than for it to accept a null reference or value. And I believe that the resulting code is more modular, more easily refactored and more reusable a result, errors are better handled, and the resulting data structures and calling arguments more easily interpreted, more readily queried and destructured, and are (so far) proving generally better fitted to real-world domains.