How To Retrieve PHP Enum Values

PHP enums are a useful feature that allows you to define a set of named constants with associated values. Enums can help you to write more concise and readable code by providing a way to define a set of related values that are semantically meaningful.

One common task when working with enums is to get a list of all the values that are defined. In this article, we'll explore some different ways to accomplish this in PHP.

Method 1: Using Reflection

One way to get all the values of an enum in PHP is to use the Reflection API. The Reflection API allows you to examine the structure of a class, including its constants.

To get a list of all the values of an enum using Reflection, you can use the following code:

php
class MyEnum {
    
   const VALUE1 = 1;
    
   const VALUE2 = 2;
    
   const VALUE3 = 3;

}



$reflection = new ReflectionClass('MyEnum');

$values = $reflection->getConstants();
print_r($values);

This will output:

csharp
Array
(
    [VALUE1] => 1
    [VALUE2] => 2
    [VALUE3] => 3
)

Method 2: Using a Static Method

Another way to get all the values of an enum in PHP is to define a static method that returns an array of the values. Here's an example:

php
class MyEnum {
    
  const VALUE1 = 1;
    
  const VALUE2 = 2;
    
  const VALUE3 = 3;

    
  public static function getValues() {
        
    return array_values((new ReflectionClass(__CLASS__))->getConstants());

  }

}



$values = MyEnum::getValues();
print_r($values);

This will output:

csharp
Array
(
    [0] => 1
    [1] => 2
    [2] => 3
)

Method 3: Using an Abstract Method

Finally, you can also define an abstract method in your enum class that returns an array of the values. Here's an example:

php
abstract class MyEnum {
    
  const VALUE1 = 1;
    
  const VALUE2 = 2;
    
  const VALUE3 = 3;

    
  abstract public static function getValues(): array;

}



class MyEnumImpl extends MyEnum {
    
  public static function getValues(): array {
        
   return array_values(get_defined_constants(true)['user'][__CLASS__]);

  }

}



$values = MyEnumImpl::getValues();

print_r($values);

This will output:

csharp
Array
(
    [0] => 1
    [1] => 2
    [2] => 3
)

Conclusion

In this article, we explored three different ways to get all the values of an enum in PHP: using Reflection, using a static method, and using an abstract method. Each method has its own advantages and disadvantages, so choose the one that best fits your needs. With these techniques, you can easily retrieve all the values of your enums and use them in your code as needed.