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
Value listing
Both Pure Enums and Backed Enums implement an internal interface named
UnitEnum. UnitEnum includes a static method
cases(). cases() returns a packed array of
all defined Cases in the order of declaration.
<?php
Suit::cases();
// Produces: [Suit::Hearts, Suit::Diamonds, Suit::Clubs, Suit::Spades]
?>Manually defining a cases() method on an Enum will result in a fatal error.
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User Contributed Notes 2 notes
theking2 at king dot ma ¶
2 years ago
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
}
