Enum

A utility library for working with enumerated types (enums). Simplify the management of constant values by creating strongly-typed enums with custom labels and values. Provides convenience methods for enum conversion, retrieval, and equality checks.

Inspired by PHP Enum.

Installation

npm install @ngekoding/enum

Usage

This is how an enum can be defined.

import Enum from '@ngekoding/enum'

class UserLevel extends Enum {
  static Basic = new UserLevel(1, 'Basic')
  static Pro = new UserLevel(2, 'Pro')
  static Premium = new UserLevel(3, 'Premium')
}

Where the first parameter is the value and the second parameter is the label.

Accessing enum values or labels

console.log(UserLevel.Basic.value) // Output: 1
console.log(UserLevel.Basic.label) // Output: Basic

Creating an enum from a value

const userLevel = UserLevel.fromValue(2)

When an enum value doesn't exist, you'll get an Error exception. If you would prefer not catching an exception, you can use:

const userLevel = UserLevel.tryFromValue(2)

When an enum value doesn't exist in this case, userLevel will have value null and label Unknown.

Comparing enums

Enums can be compared using the equals method:

console.log(userLevel.equals(UserLevel.Pro)) // Output: true

You can pass several enums to the equals method, it will return true if the current enum equals one of the given values.

console.log(userLevel.equals(UserLevel.Pro, UserLevel.Premium)) // Output: true

You can safely comparing enum even there is no enum value when using tryFromValue.

console.log(UserLevel.tryFromValue(0).equals(UserLevel.Basic)) // Output: false

Get an array of enum instances

You can get an array containing all the enum instances defined within the enum class. This is allows easy access to the entire set of enum values.

const values = UserLevel.values()
console.log(values) // Output: [UserLevel.Basic, UserLevel.Pro, UserLevel.Premium]