BackedEnum

The BackedENum interface identifies an enumeration with a string or int value. It works only on backed-enumerations.

This interface is only available for type checks, and cannot be implemented by another class.

This interface ensure the enum::tryFrom() and enum::from() methods and the enum::$value property are available, to convert from and to scalars.

<?php

enum E { case A;}
enum F: int { case B = 1;}

var_dump(E::A instanceof BackedEnum); // false
var_dump(F::B instanceof BackedEnum); // true

?>

Documentation

See also Use the PHP UnitEnum::cases() during testing.

Related : Enumeration (enum), UnitEnum, String, integer, Interface, PHP Native Interfaces, Unbacked Enum