Enum::cases() & Enum from()/tryFrom()

TL;DR

Explanation

UnitEnum::cases() returns an array of all enum cases. BackedEnum::from(string|int) returns the matching case or throws ValueError. BackedEnum::tryFrom() returns null instead of throwing. Use cases() to build select options, from() when the value should always be valid, tryFrom() when handling user input that may be invalid. Pure enums only have cases() — no from()/tryFrom(). PHP 8.3 added typed enum constants.

Common Misconception

Why It Matters

Common Mistakes

• Using from() on untrusted user input — throws ValueError.
• Calling tryFrom() on a pure (unit) enum — method doesn't exist.
• Not using cases() for building form options — manually listing cases duplicates the enum.

Code Examples

// Unsafe — throws ValueError on invalid input:
$status = Status::from($request->get('status'));

// Building options manually — duplicates enum:
$options = ['active' => 'Active', 'inactive' => 'Inactive'];

// Safe user input:
$status = Status::tryFrom($request->get('status')) ?? Status::Active;

// Build options from enum:
$options = array_column(
    array_map(fn(Status $s) => ['value' => $s->value, 'label' => $s->getLabel()], Status::cases()),
    'label', 'value'
);

References

• ↗ https://www.php.net/manual/en/language.enumerations.backed.php

Tags

Related Terms