## Serialization

Enumerations are serialized differently from objects. Specifically, they have a new serialization code, `"E"`, that specifies the name of the enum case. The deserialization routine is then able to use that to set a variable to the existing singleton value. That ensures that:

    <?php

    enum Suit: string
    {
        case Hearts = 'H';
        case Diamonds = 'D';
        case Clubs = 'C';
        case Spades = 'S';
    }

    Suit::Hearts === unserialize(serialize(Suit::Hearts));

    print serialize(Suit::Hearts);
    // E:11:"Suit:Hearts";

On deserialization, if an enum and case cannot be found to match a serialized value a warning will be issued and `false` returned.

The `allowed_classes` option of unserialize() does not affect Enumerations.

If a Pure Enum is serialized to JSON, an error will be thrown. If a Backed Enum is serialized to JSON, it will be represented by its scalar value only, in the appropriate type. The behavior of both may be overridden by implementing JsonSerializable.

For print_r(), the output of an enum case is slightly different from objects to minimize confusion.

    <?php

    enum Foo
    {
        case Bar;
    }

    enum Baz: int
    {
        case Beep = 5;
    }

    print_r(Foo::Bar);
    print_r(Baz::Beep);

    /* Produces

    Foo Enum (
        [name] => Bar
    )
    Baz Enum:int {
        [name] => Beep
        [value] => 5
    }
    */

`↑` and `↓` to navigate • `Enter` to select • `Esc` to close • `/` to open