Java

Nil vs Null

In Java the most “popular” error is java.lang.NullPointerException. The problem is so pervasive, so bad, that there are even things like java.util.Optional and com.google.common.base.Optional. The purpose (insofar as I understand it) is to get callers of methods to actually check if something was returned by a method call. The problem is that every object variable (any variable that is not a for a primitive type) in Java is actually a reference, that is, a pointer.