JavaScript

From absolute beginner to advanced JavaScript.

Beginner

  1. What is JavaScript?: The programming language that makes websites interactive.
  2. Variables: A named container for storing a value your program can reuse.
  3. Data Types: The different kinds of values JavaScript can store and work with.
  4. Operators: Symbols that perform actions on values, like math or comparisons.
  5. Conditions: Making your code choose between different paths based on a test.
  6. Loops: Repeating an action multiple times without copy-pasting code.
  7. Functions: A reusable, named block of code that performs a specific task.

Intermediate

  1. Arrays: An ordered list of values, stored in a single variable.
  2. Objects: A collection of related values, stored as named properties.
  3. Scope: The rules that decide where a variable can be used in your code.
  4. Closures: A function that remembers the variables from where it was created, even after that outer code has finished running.
  5. Array Methods (forEach, map, filter, reduce...): The built-in tools for looping over, transforming, and summarizing arrays without writing manual loops.
  6. String Methods: The built-in tools for reading, searching, and reshaping text.
  7. Callbacks: A function you pass into another function, to be called later — often once some work finishes.
  8. Higher-Order Functions: A function that takes another function as input, returns one as output, or both.
  9. Destructuring & Spread/Rest: Quick ways to pull values out of arrays/objects, and to expand or collect values using ...

Advanced

  1. Promises: An object that represents a value you'll get later, not right now.
  2. Async/Await: A cleaner way to write asynchronous code so it reads like normal, step-by-step code.
  3. Event Loop: The mechanism that lets JavaScript handle many tasks without ever running two at once.
  4. Prototypes: How JavaScript objects share behavior with each other behind the scenes.
  5. this: A special keyword that refers to whatever object is currently 'in charge' of the running code.
  6. Common JavaScript Confusions: A collection of surprising JavaScript behaviors that trip up almost everyone at some point.
  7. Error Handling: Dealing with things that go wrong in your code on purpose, instead of letting the program crash.
  8. Modules: Splitting code across multiple files, and sharing pieces between them deliberately.
  9. Memory Management: How JavaScript decides when a piece of data is no longer needed and can be cleaned up.
  10. Optional Chaining & Nullish Coalescing: Safely reading deeply nested properties, and providing defaults, without a pile of manual checks.
  11. JSON: A simple, text-based format for representing data, used constantly to send information between programs.
  12. Map and Set: Two built-in collections — Map for key-value pairs, Set for unique values — that improve on what plain objects and arrays can do.