PHP: Listagem de valores

Listagem de valores

Tanto Pure Enums quanto Backed Enums implementam uma interface interna chamada UnitEnum. UnitEnum inclui um método estático cases(). cases() retorna um array embalado com todos os Casos definidos na ordem de declaração.

<?php

Naipe::cases();
// Produz: [Naipe::Copas, Naipe::Ouros, Naipe::Paus, Naipe::Espadas]
?>

Definir manualmente um método cases() em uma Enum resultará em um erro fatal.

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User Contributed Notes 2 notes

down

theking2 at king dot ma ¶

1 year ago

As ::cases() creates a Iteratable it is possible to use it in a foreach loop. In combination with value backed enum this can result in very compact and very readable code:

<?php
/** Content Security Policy directives */
enum CspDirective: String {
  case Default = "default-src";
  case Image = "img-src";
  case Font = "font-src";
  case Script = "script-src";
  case Style = "style-src";
}

/** list all CSP directives */
foreach( CspSource::cases() as $directive ) {
  echo $directive-> value . PHP_EOL;
}
?>
Which results in:
default-src
img-src
font-src
script-src
style-src

down

-11

ratsimbasitraka at gmail dot com ¶

1 year ago

enum Priority {
    case Left;
    case Right;
}

// Does not work as default parameter
public function selectPriorities(array $priorities = Priority::cases()) {
    Priority::cases() // works here
}

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