Null

The value null is a reference that does not refer to anything.

Related concepts:  ValueReference

Closest Wikipedia entry:  Null pointer

Misconceptions about Null

6 documented Misconceptions

NullIsObject — Java

null is an object

OutOfBoundsElementsAreNull — Java

Out-of-bounds array elements are null

ThisCanBeNull — Java

this can be null

ThisInConstructorIsNull — Java

In a constructor, this is null

NullAndUndefinedAreTheSame — JavaScript

The values null and undefined are the same

NullIsObject — JavaScript

null is an object