Week 2 — JS Functions & Arrays

intermediate javascript dsa dbms

Goal: Master JavaScript function patterns and start working with core data structures and database fundamentals.

Topics

DayFocusTopics
MonJS Closures & CurryingClosures · Currying · Memoization
TueJS Function Contextcall, apply, bind · IIFE · Lexical Scope
WedDSA Arrays & StringsArrays & Operations · Strings & Pattern Matching
ThuDSA Hash MapsHash Maps & Sets
FriDBMS BasicsWhat Is a DBMS? · Types of Databases · SQL vs NoSQL

Key Concepts

  • Closures and their classic interview patterns (counter, private variables, loop traps)
  • When to reach for call vs apply vs bind — and why they exist
  • Memoization as a caching strategy for expensive function calls
  • Hash map O(1) lookups and how they unlock elegant solutions to array problems
  • SQL vs NoSQL tradeoffs — when to pick which, and why it matters

Practice

  • Implement Function.prototype.bind from scratch (this one comes up a lot)
  • Write a generic memoize() function that works with any pure function
  • Solve 2 array problems using hash maps (e.g., two sum, group anagrams)
  • Compare SQL and NoSQL for 3 real scenarios — justify your picks

~12 topics · ~1.5 hrs/day · Focus: read the linked notes, then code each concept