Enumerations may also have static methods. The use for static methods on the enumeration itself is primarily for alternative constructors. E.g.:
<?php
enum Size
{
case Small;
case Medium;
case Large;
public static function fromLength(int $cm): static
{
return match(true) {
$cm < 50 => static::Small,
$cm < 100 => static::Medium,
default => static::Large,
};
}
}
?>Static methods may be public, private, or protected, although in practice private and protected are equivalent as inheritance is not allowed.
To get all scalar equivalents values of Backed Enum as an array you could define a method in your Enum:
<?php
enum Suit: string
{
case Hearts = 'H';
case Diamonds = 'D';
case Clubs = 'C';
case Spades = 'S';
public static function values(): array
{
return array_column(self::cases(), 'value');
}
}
?>Need to retrieve all the names and values immediately from a backed enum (for something like a select box) and you don't want to loop over `Enum::cases()`? Try this:
<?php
enum Suit: string
{
case Hearts = 'H';
case Diamonds = 'D';
case Clubs = 'C';
case Spades = 'S';
public static function forSelect(): array
{
return array_combine(
array_column(self::cases(), 'value'),
array_column(self::cases(), 'name')
);
}
}
Suit::forSelect();
?>
Put `forSelect()` in a trait and use it in any enum you have that needs this functionality.