PHP and Enums

I know that PHP doesn't have native Enumerations. But I have become accustomed to them from the Java world. I would love to use enums as a way to give predefined values which IDEs' auto completion features could understand.

How to enumerate an enum?

How can you enumerate a enum in C#?

e.g. the following does not compile:

Generics using Enum in Java

I have an enum

public enum Days {

SUNDAY, MONDAY, TUESDAY, WEDNESDAY,

THURSDAY, FRIDAY, SATURDAY