Goal: Understand how JavaScript actually runs your code, get comfortable with async patterns, and start writing SQL that does real work.
Topics
| Day | Focus | Topics |
|---|---|---|
| Mon | JS Execution Model | Execution Context · The this Keyword · Shallow Copy & Deep Copy |
| Tue | JS Async Basics | Callbacks · Promises |
| Wed | JS Async Advanced | Async/Await · Promise Methods |
| Thu | SQL Querying | ACID Properties · DDL, DML & DCL · Joins · Aggregations & GROUP BY |
| Fri | DSA Techniques | Prefix Sum & Difference Arrays · Matrix Problems |
Key Concepts
- How
thischanges based on call context — global, method, arrow, explicit binding - Execution context creation (memory phase vs execution phase)
- Promise chaining vs async/await — same thing, different syntax, different readability
Promise.allvsPromise.allSettledvsPromise.race— know when to use each- ACID guarantees and why they matter for data integrity
- Types of SQL joins — inner, left, right, full, cross — and when each makes sense
- Prefix sum technique for O(1) range queries
Practice
- Predict the value of
thisin 5 different scenarios (method call, arrow in object, class, setTimeout, explicit bind) - Convert a callback-hell example to clean async/await code
- Write JOIN queries for 3 scenarios: user orders, employee departments, optional relationships
- Solve a prefix sum problem (e.g., subarray sum equals K)
~13 topics · ~2 hrs/day · Focus: read the linked notes, then code each concept