| # | title | topic | type | difficulty |
|---|---|---|---|---|
| 31 | Static methods don't reach instances | Quiz: JS Questions | Multiple choice | Medium |
| 32 | Insertion sort, in place | Sorting Algorithms | Coding | Medium |
| 33 | Tagged templates: redact the interpolations | YDKJS Book | Coding | Medium |
| 34 | Two Sum in one pass | Interview Classics | Coding | Medium |
| 35 | Balanced brackets with a stack |
| Interview Classics |
| Coding |
| Medium |
| 36 | Pair sum — approach 2: classic loops only | Arrays | Coding | Medium |
| 37 | Deep flatten — approach 2: recursion, no .flat() | Arrays | Coding | Medium |
| 38 | Deep max — approach 2: reduce(), Math.max banned | Math | Coding | Medium |
| 39 | Multiplication table — approach 2: nested for loops | Arrays | Coding | Medium |
| 40 | Weighted sum — approach 2: reduce(), no loops | Loops | Coding | Medium |
| 41 | Reverse an integer — approach 2: string methods | Loops | Coding | Medium |
| 42 | Collatz steps — approach 2: pure recursion | Loops | Coding | Medium |
| 43 | Tokenizer — approach 2: classic loops, no array methods | Arrays | Coding | Medium |
| 44 | Grid validation — approach 2: nested for loops | Arrays | Coding | Medium |
| 45 | Function composition — approach 2: a plain loop | Arrays | Coding | Medium |
| 46 | Depth-first search: recursive traversal | Algorithms & Recursion | Coding | Medium |
| 47 | The accidentally quadratic accumulator | Patterns & Performance | Multiple choice | Medium |
| 48 | Kill the O(n²) lookup | Patterns & Performance | Coding | Medium |
| 49 | Plain object or Map? | Patterns & Performance | Multiple choice | Medium |
| 50 | Observer pattern with unsubscribe | Patterns & Performance | Coding | Medium |
| 51 | Prototype pattern: share the methods | Patterns & Performance | Coding | Medium |
| 52 | Mixin pattern: compose behaviors | Patterns & Performance | Coding | Medium |
| 53 | script: async vs defer | Web Platform | Multiple choice | Medium |
| 54 | Two async functions interleave | Event Loop & Memory | Drag & drop | Medium |
| 55 | Stack frames and the heap | Event Loop & Memory | Multiple choice | Medium |
| 56 | Test the tester: dedupe() | Unit Testing | Write the tests | Medium |
| 57 | Test the tester: clamp() | Unit Testing | Write the tests | Medium |
| 58 | Test the tester: slugify() | Unit Testing | Write the tests | Medium |
| 59 | Test the tester: once() | Unit Testing | Write the tests | Medium |
| 60 | Test the tester: fizzBuzz() | Unit Testing | Write the tests | Medium |