In this Hasty Treat, Scott and Wes talk about enums in JS — what they are, what they do, and how they work in JavaScript.

LogRocket - Sponsor

LogRocket lets you replay what users do on your site, helping you reproduce bugs and fix issues faster. It’s an exception tracker, a session re-player and a performance monitor. Get 14 days free at logrocket.com/syntax.

Show Notes

03:11 - What are enums?

A type restricting variables to one value from a predefined set of constants
Direction = UP / DOWN / LEFT / RIGHT
Role = ADMIN EDITOR AUTHOR VIEWER
Day of the Week

05:12 - In GraphQL

enum Role { ADMIN EDITOR AUTHOR VIEWER}
Then

07:05 - In TypeScript

First, declare the type:
- enum direction = { UP, DOWN, LEFT, RIGHT }
Then when you defined your function, use that type
- type User { role: Role } or type User { role: [Role] }

08:49 - In JavaScript

Not in JS yet
There is a proposal in stage 1
- https://github.com/rbuckton/proposal-enum
And a babel plugin:
- https://www.npmjs.com/package/babel-plugin-const-enum
Can use case/switch
Can use Object or Map keys

Links

Syntax 287: Hasty Treat - Records and Tuples in JavaScript

Tweet us your tasty treats!

Scott’s Instagram
LevelUpTutorials Instagram
Wes’ Instagram
Wes’ Twitter
Wes’ Facebook
Scott’s Twitter
Make sure to include @SyntaxFM in your tweets

Hasty Treat - Enums in JS (GraphQL and Typescript)

Syntax - Tasty Web Development Treats