What would we do without NULL?

Question

I once read that having nullable types is an absolute evil. I believe it was in an article written by the very person who created them(in Ada?) I believe this is the article

Answer 1

Haskell is a powerful language that doesn't have the concept of nullity. Basically, every variable must be initialized to a non-null value. If you want to represent an "optional" variable (the variable may have a value but it may not), you can use a special "Maybe" type.

It's easier to implement this system in Haskell than C# because data is immutable in Haskell so it doesn't really make sense to have a null reference that you later populate. However, in C#, the last link in a linked list may have a null pointer to the next link, which is populated when the list expands. I don't know what a procedural language without null types would look like.

Also, note that many people above seem to be suggesting replacing nulls with type-specific logical "nothing" values (999-999-9999, "NULL", etc.). These values don't really solve anything because the problem people have with nulls is that they are a special case but people forget to code for the special case. With the type-specific logical nothing values, people STILL forget to code for the special case, yet they avoid errors that catch this mistake, which is a bad thing.