Type Hierarchy

Types in Flow form a hierarchy based on subtyping:

Click on a node to go to the documentation for that type.

Types appearing higher in this graph are more general, while those appearing lower are more specific. An arrow pointing from type A to type B means that A is a subtype of B. For example, the type string is a subtype of ?string.

How can any be at both the top and the bottom? Because it is unsafe. This is denoted with a dotted line.