Posted on Jul 2

This Is How I Mastered TypeScript Like I'm 5 (Enums!)(9)

#webdev #javascript #typescript #beginners

Today! We’re going to continue TypeScript learning like you’re a smart 5-year-old who loves to build things and asks “why?” (which is the best thing ever).

& yes “why?” is my way of learning.

I've divided this into 20 Chapters. and will go one by one and each will be of 2 - 3 min. of read.
This is a Continuation. if you have not read the Previous chapter - Chapter 8

🧩 Chapter 9: Enums

(aka: “Giving numbers and strings meaningful values for your app.”)

🎨 Imagine This:

You’re making a game with four difficulties:

Easy
Medium
Hard
Impossible

You could:

Use "easy", "medium", etc. everywhere (but risk typos like "medum")
Use numbers like 1, 2, 3, 4 (but you’ll forget which is which)

Enums help you give names to these values and keep them organized.

🚦 What is an Enum?

An Enum is like a labeled list of values you can use in your code.

🧪 Basic Enum Example:

enum Difficulty { Easy, Medium, Hard, Impossible, } let gameLevel: Difficulty = Difficulty.Medium; console.log(gameLevel); // 1 (because Easy=0, Medium=1, ...)

🤝 Why use Enums?

✅ Readability: Difficulty.Medium is clearer than "medium" or 1.
✅ Safety: Prevents typos ("medum" ❌).
✅ Organized: All values live in one place.

Production Example: Enums for User Roles in an App

Imagine you’re building a team management SaaS.
Users can have roles like:

Admin
Editor
Viewer

Using Enums, you can cleanly manage permissions.

🚦 Step 1: Define the Enum

// userRoles.ts export enum UserRole { Admin = "ADMIN", Editor = "EDITOR", Viewer = "VIEWER", }

🚦 Step 2: Use it in your user model

// models/user.ts import { UserRole } from "./userRoles"; type User = { id: string; name: string; email: string; role: UserRole; }; const user: User = { id: "u123", name: "Karandeep Singh", email: "karandeep@wisdimbits.com", role: UserRole.Editor, };

🚦 Step 3: Permission checks in services

// services/checkPermission.ts import { UserRole } from "./userRoles"; function canEditContent(role: UserRole) { return role === UserRole.Admin || role === UserRole.Editor; } // Usage if (canEditContent(user.role)) { console.log("User can edit content"); } else { console.log("User can only view content"); }

🌱 Summary

Using enums for roles, statuses, modes, environment constants, and permission levels is a best practice in production TypeScript apps to:
✅ Reduce bugs
✅ Improve clarity
✅ Enable safe refactoring later.