🚀 JavaScript Job-Ready Roadmap

Complete Study Guide for Full-Stack Development (1-2 Weeks)

🎯 OVERVIEW

This roadmap covers the 90% most-used JavaScript concepts in real web development jobs. Focus on understanding these topics thoroughly to become job-ready and master your existing projects.

1. CORE JAVASCRIPT FUNDAMENTALS

Variables & Data Types

let, const, var (scope differences)
Primitive types: string, number, boolean, null, undefined, symbol
Reference types: object, array, function
Type checking: typeof, instanceof

Functions

Function declarations vs expressions
Arrow functions: () => {}
Parameters: default, rest (...args), destructuring
Return statements
this binding in different contexts
IIFE (Immediately Invoked Function Expressions)

Objects

Object creation: literal, new Object(), Object.create()
Property access: dot notation, bracket notation

Essential Methods:

Object.keys()
Object.values()
Object.entries()
Object.assign()

Spread operator {...obj}
Destructuring: const {name, age} = user
Computed property names

Arrays CRITICAL

Essential Methods You Must Know:

push(), pop(), shift(), unshift()
slice(), splice()
map(), filter(), reduce(), forEach()
find(), findIndex(), some(), every()
includes(), indexOf(), join(), sort()
concat(), spread operator [...arr]
Array destructuring: const [first, second] = arr

2. CONTROL FLOW & LOOPS

if/else, switch, ternary operator
for, for...in, for...of, while, do...while
break, continue

3. ERROR HANDLING

try, catch, finally
throw statements
Error objects and custom errors
Promise error handling

4. ASYNCHRONOUS JAVASCRIPT CRITICAL

Promises

new Promise(), resolve(), reject()
.then(), .catch(), .finally()
Promise chaining

Promise API Methods:

Promise.all()
Promise.race()
Promise.allSettled()

Async/Await

async functions
await keyword
Error handling with try/catch
Converting promises to async/await

Timers

setTimeout(), clearTimeout()
setInterval(), clearInterval()

5. DOM MANIPULATION CRITICAL FOR YOUR PROJECTS

Element Selection

document.getElementById()
document.querySelector(), document.querySelectorAll()
document.getElementsByClassName(), document.getElementsByTagName()

Element Manipulation

element.textContent, element.innerHTML
element.setAttribute(), element.getAttribute()

ClassList Methods:

element.classList.add()
element.classList.remove()
element.classList.toggle()
element.classList.contains()

element.style.property
element.dataset

Element Creation & Modification

document.createElement()
element.appendChild(), element.removeChild()
element.insertBefore(), element.replaceChild()
element.remove()
document.createDocumentFragment()

Event Handling

addEventListener(), removeEventListener()

Event Object Properties:

event.target
event.preventDefault()
event.stopPropagation()

Common Events: click, input, change, submit, DOMContentLoaded
Event delegation

6. MODULES USED IN YOUR PROJECTS

export (named and default exports)
import statements
Dynamic imports: import()
Module patterns (IIFE modules like in your projects)

7. JSON & DATA HANDLING

JSON.stringify(), JSON.parse()
Working with APIs and JSON responses

Local Storage:

localStorage.getItem()
localStorage.setItem()
localStorage.removeItem()

8. HTTP REQUESTS & APIs CRITICAL FOR BACKEND INTEGRATION

Fetch API

fetch() basics
Request Methods: GET, POST, PUT, DELETE
Headers and request configuration

Response Methods:

.json()
.text()
.blob()

Error handling with fetch

Async Data Patterns

Loading states
Error states
Data transformation

9. FIREBASE INTEGRATION YOUR PROJECTS USE THIS

Firebase initialization

Authentication:

auth.signInWithEmailAndPassword()
auth.createUserWithEmailAndPassword()
auth.signOut()
auth.onAuthStateChanged()

Database:

database.ref()
.set(), .update(), .remove()
.on(), .once()

Real-time listeners

10. COMMON PATTERNS FROM YOUR PROJECTS

Module Pattern

      const ModuleName = (() => { // Private variables/functions const init = ()
      => { /* ... */ }; // Public API return { init, publicMethod }; })();
    

Event-Driven Architecture

Setting up event listeners
Managing multiple event handlers
Form handling and validation

State Management

Managing application state in variables
State updates and UI synchronization

11. NODE.JS BASICS FOR YOUR PAYMENT GATEWAY PROJECT

Core Modules

require() and module.exports
http module for server creation
fs module for file operations
path module

Express.js Essentials

Route Handling:

app.get(), app.post(), app.put(), app.delete()

Middleware: app.use()

Request/Response:

req.body, req.params, req.query
res.json(), res.status(), res.send()

CORS handling

API Development

RESTful API principles
Request validation
Error handling middleware
Environment variables (process.env)

12. PAYMENT GATEWAY INTEGRATION

API request/response handling
Webhook verification
Order creation and payment verification
Security considerations (API keys, signatures)

13. COMMON UTILITIES

String Methods

split(), trim(), replace(), includes()
startsWith(), endsWith(), toLowerCase(), toUpperCase()

Number Methods

parseInt(), parseFloat(), toFixed(), Math.floor(), Math.ceil()

Date Handling

new Date(), .getTime(), .toLocaleDateString()
Date formatting and manipulation

Regular Expressions (Basic)

Pattern matching for validation
Common patterns for email, phone, etc.

14. ES6+ FEATURES MODERN JAVASCRIPT

Template literals: `Hello ${name}`
Destructuring assignment
Spread operator: ...
Default parameters
Arrow functions
const/let vs var
Enhanced object literals

📅 STUDY PLAN (1-2 WEEKS)

Week 1: Fundamentals + Core Skills

Days 1-3: Topics 1-4 (Variables, Functions, Objects, Arrays, Async)
Days 4-5: Topics 5-6 (DOM Manipulation, Modules)
Days 6-7: Topics 7-8 (JSON, APIs, Fetch)

Week 2: Framework & Project Skills

Days 8-10: Topics 9-11 (Firebase, Node.js, Express)
Days 11-12: Topics 12-14 (Payment Integration, Utilities, ES6+)
Days 13-14: Practice - Rebuild project features from scratch

🎯 DAILY PRACTICE GOALS

Morning: Study 2-3 topics from the list
Afternoon: Practice with small coding exercises
Evening: Apply concepts to rebuild features from your projects

✅ PROJECT UNDERSTANDING CHECKLIST

After completing this roadmap, you should be able to:

☐ Explain every line of code in your Food Tracker project
☐ Rebuild the user authentication system from scratch
☐ Create new Firebase database operations
☐ Build API endpoints for payment processing
☐ Handle form submissions and data validation
☐ Implement real-time data updates
☐ Manage application state across modules
☐ Debug and fix common JavaScript issues

🚀 SUCCESS TIPS

Focus on understanding, not memorizing
Practice each method with real examples
Build small projects for each topic
Code along with your existing projects
Ask yourself "why" for every concept

Master these topics and you'll be ready for 90% of JavaScript job interviews and can confidently work on any web development Master these topics and you'll be ready for 90% of JavaScript job interviews and can confidently work on any web development