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<UnitEnum::casesBackedEnum::from>
^Predefined Interfaces and ClassesLast updated: Mon, 26 Oct 2026

The BackedEnum interface

(PHP 8 >= 8.1.0)

Introduction

The BackedEnum interface is automatically applied to backed enumerations by the engine. It may not be implemented by user-defined classes. Enumerations may not override its methods, as default implementations are provided by the engine. It is available only for type checks.

Interface synopsis

interface BackedEnum extends UnitEnum {
/* Methods */
public static function from(int|string $value): static
public static function tryFrom(int|string $value): ?static
/* Inherited methods */
public static function UnitEnum::cases(): array
}

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<UnitEnum::casesBackedEnum::from>
^Predefined Interfaces and ClassesLast updated: Mon, 26 Oct 2026