peachpie-docs/docs/net/enums.md

The .NET languages support enums natively and the compiler provides an easy way of making use of them. However, it is neither possible to define enum in PHP code yet nor to perform an Enum.ToString() conversion.

Using enum in PHP code

Within the context of PHP code, enum is treated as a final class with class constats. Its usage from PHP code is thus analogous.

C# code:

public enum DayOfWeek {
	Sunday,
	Monday,
	Tuesday,
	Wednesday,
	Thursday,
	Friday,
	Saturday
}

PHP code:

<?php

echo DayOfWeek::Monday; // prints 1

Defining enum in PHP code

Not supported