What are Enums in TypeScript?

Enums in TypeScript are not a type-level extension of JavaScript. Enums are a set of named constants.

Enums are immutable. It also provides a few things:

  • a closed set of well known values
  • a respective set of literal-like types for each member
  • by a single named type which encompasses all values

Enums make it easier to document intent or create a set of distinct cases. TypeScript provides both numeric and string-based enums.

Example of Enum

enum subscriberState {
    Inactive,
    Active,
    Expired,
    Unknown
}

const activeState = subscriberState.Active;
console.log(activeState);