Examples

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## Examples

Example #1 Basic limited values

    <?phpenum SortOrder{    case Asc;    case Desc;}function query($fields, $filter, SortOrder $order = SortOrder::Asc) { ... }?>

The `query()` function can now proceed safe in the knowledge that `$order` is guaranteed to be either `SortOrder::Asc` or `SortOrder::Desc`. Any other value would have resulted in a TypeError, so no further error checking or testing is needed.

Example #2 Advanced exclusive values

    <?phpenum UserStatus: string{    case Pending = 'P';    case Active = 'A';    case Suspended = 'S';    case CanceledByUser = 'C';    public function label(): string    {        return match($this) {            static::Pending => 'Pending',            static::Active => 'Active',            static::Suspended => 'Suspended',            static::CanceledByUser => 'Canceled by user',        };    }}?>

In this example, a user's status may be one of, and exclusively, `UserStatus::Pending`, `UserStatus::Active`, `UserStatus::Suspended`, or `UserStatus::CanceledByUser`. A function can type a parameter against `UserStatus` and then only accept those four values, period.

All four values have a `label()` method, which returns a human-readable string. That string is independent of the "machine name" scalar equivalent string, which can be used in, for example, a database field or an HTML select box.

    <?phpforeach (UserStatus::cases() as $case) {    printf('<option value="%s">%s</option>\n', $case->value, $case->label());}?>