Weakmap And Enums

By Dmitri Goosens

<?php

enum WeekDay: string
{
    case Monday = 'monday';
    case Tuesday = 'tuesday';
    case Wednesday = 'wednesday';
    case Thursday = 'thursday';
    case Friday = 'friday';
    case Saturday = 'saturday';
    case Sunday = 'sunday';
}

class Foo
{
    public function hello()
    {
        return "Hello world" . PHP_EOL;
    }
}

$array = [];
$array[WeekDay::Monday->value] = new Foo();
// etc

echo $array[WeekDay::Monday->value]->hello();

$map = new WeakMap();
$map[WeekDay::Monday] = new Foo();
// etc

echo $map[WeekDay::Monday]->hello();

Have been reminded by a fellow PHP dev that, instead of a simple array, one could also use WeakMap…

Nice thing with this is that it is a real dictionary… and that it accepts objects as keys… and this includes Enum::case.

See Also

• Original toot

• Weakmap (PHP manual)

• Weakmap in action [Try me]

PHP Features

• weakmap

• enum

• array

Last updated: 14 July 2026