Progsity
৳1,999 onceFrom zero

Learn JavaScript

Lessons
59
Modules out
7 of 19
Parts
6

Who can read what

Free · 34
Anyone can read it, signed in or not.
Free with an account · 10
Free to read once you have an account.
Pro · 15
Included with this track or with Learn Pro.

What is inside

19 modules in 6 parts, 7 of them out so far. Lessons with no mark are free to read.

Part Zero

What JavaScript is

2 modules · 14 lessons

    1. What JavaScript Is (and Why It Is Not Java)Reading
    2. Where It Runs: Browser, Server, Phone, DesktopReading
    3. The Job Market, Honestly: What JavaScript Gets You and What It Does NotReading
    4. How the Engine Runs Your Code: Parse, Bytecode, JITReading
    5. Your First Run: The Console, Node, and the PlaygroundReading
    6. Module Test: What JavaScript IsModule test

    1. A Program Line by Line: console.log, Numbers and TextReading
    2. let and const: A Name for a Value, and Why Not varReading
    3. The Seven Primitives and One ObjectReading
    4. typeof, undefined and null: Asking a Value What It IsReading
    5. Reading Input: The Starter Every Problem Uses, Line by LineReading
    6. Comments, Names and Code a Human Can ReadReading
    7. Problems: First ProgramsProblems
    8. Module Test: First ProgramsModule test

Part One

The language, piece by piece

3 modules · 27 lessons

    1. Two Values Meet an Operator: The PictureReading
    2. Every Operator, One by OneReading
    3. Full Programs: Converting on PurposeReading
    4. When to Use == and When Not, and the Other Judgement CallsReading
    5. Under the Hood: The Abstract Equality Algorithm and Floating PointProReading
    6. Interview Pack: Output Puzzles, the Questions and the Bug GalleryProReading
    7. Problems: Types and CoercionProblems
    8. Cheat Sheet: Types, Operators and Coercion on One PageProReading
    9. Module Test: Types and CoercionModule test

    1. A String Is a Row of Code Units: The PictureReading
    2. Every String Method, One by OneReading
    3. Full Programs: Strings at WorkReading
    4. When to Use Which: Methods or a Loop, a Template or +, and When It Is a RegexReading
    5. Under the Hood: Immutability, Ropes and UTF-16ProReading
    6. CP and Interview Pack: String Patterns, the Questions and the Bug GalleryProReading
    7. Problems: StringsProblems
    8. Cheat Sheet: Strings on One PageProReading
    9. Module Test: StringsModule test

    1. Decisions and Loops: The PictureReading
    2. Every Statement, One by OneReading
    3. Full Programs: From FizzBuzz to a Prime SieveReading
    4. Which Loop, and When switch Beats ifReading
    5. Under the Hood: Loops as Jumps, the Iterator Protocol and a Loop LabProReading
    6. CP and Interview Pack: Nested Loops, Early Exit and the Bug GalleryProReading
    7. Problems: if, switch and LoopsProblems
    8. Cheat Sheet: if, switch and Loops on One PageProReading
    9. Module Test: if, switch and LoopsModule test

Part Two

Functions and data

4 modules · 18 lessons

    1. A Function Is a Named Recipe: The PictureReading
    2. Every Form, One by One: Declarations, Arrows, Defaults and RestFree with an accountReading
    3. Full Programs: A Small Library, Functions as Values and RecursionFree with an accountReading
    4. When to Use Which: Declaration or Arrow, a Default or a Check, Recursion or a LoopFree with an accountReading
    5. Under the Hood: The Call Stack, Frames and What a Call CostsProReading
    6. CP and Interview Pack: Recursion Patterns, Currying and the Bug GalleryProReading
    7. Problems: FunctionsFree with an accountProblems
    8. Cheat Sheet: Functions on One PageProReading
    9. Module Test: FunctionsFree with an accountModule test

    1. Where a Name Lives: Scope and Closures, the PictureReading
    2. Every Rule, One by One: Blocks, var, Hoisting and the Dead ZoneFree with an accountReading
    3. Full Programs: Counters, once, Private State and MemoiseFree with an accountReading
    4. When a Closure, When a Class, When a ModuleFree with an accountReading
    5. Under the Hood: Environment Records, V8 Contexts and a Closure Memory LabProReading
    6. CP and Interview Pack: The Loop Question, Hoisting Puzzles and the Bug GalleryProReading
    7. Problems: Scope, Hoisting and ClosuresFree with an accountProblems
    8. Cheat Sheet: Scope, Hoisting and Closures on One PageProReading
    9. Module Test: Scope, Hoisting and ClosuresFree with an accountModule test
  3. Module 7: Arrays and the Array Methods: The map, filter, reduce PipelineBeing written
  4. Module 8: Objects, Destructuring, Spread and JSONBeing written

Part Three

The parts people get wrong

5 modules

Being written

  • 09this, Prototypes and Classes
  • 10Error Handling: throw, try, catch, finally, and Reading a Stack Trace
  • 11Modules: import, export and How Files Find Each Other
  • 12Async 1: Callbacks and the Event Loop
  • 13Async 2: Promises, async/await and fetch

Part Four

The browser

2 modules

Being written

  • 14The DOM and Events: JavaScript Touches the Page
  • 15Forms, Storage and Small Apps

Part Five

JavaScript in the real world (Pro)

3 modules

Being written

  • 16Map, Set, WeakMap, Iterators, Generators and Regular Expressions
  • 17Performance, Memory, Debugging and the Interview Output Puzzles
  • 18Three Projects: A Todo List, a Weather App, a Quiz Game

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Certificates

How certificates work

A certificate is not issued for finishing the lessons. It is issued on a Skill Test.

Skill Test is not open yet

Timed, in the browser

Questions are drawn at random from a large pool, and the clock runs from the first one.

Your code, hidden tests

Your code runs against tests you cannot see, and submissions are compared for similarity afterwards.

A score, not a tick

The score, 0 to 1000, is printed on the certificate with the band it falls in.

Not proctored, and it says so. Identity is the account and the name on the certificate. There is no webcam and no ID check, and the certificate and its verify page both state that.

Score bands

Score is 0 to 1000, across three sections: concepts, read and debug, build.

  • Not yetRetake0–399
  • FoundationRetake400–599
  • WorkingCertificate issued600–749
  • ProficientCertificate issued750–899
  • AdvancedCertificate issued900–1000

For employers

Hiring someone?

Every certificate has a public page carrying the score, the three sections, the date and the test version. Ask for the link, not a screenshot.

Progsityprogsity.io/verify/…
Name
Track
Learn JavaScript
Score
/ 1000, with its band
Sections
Concepts · Read and debug · Build
Date, version
What the public page shows. No sample score is printed here on purpose.

Curriculum and chapter plan by Abu Jafar Md Jakaria, based on the author's own lecture notes and teaching materials. Drafted with AI writing tools, then edited and approved by the author.