| # | title | topic | type | difficulty |
|---|---|---|---|---|
| 1 | Build bind() yourself (hard binding) | YDKJS Book | Coding | Hard |
| 2 | curry(fn) — collect arguments until arity is met | YDKJS Book | Coding | Hard |
| 3 | memoize(fn) — cache by identity, even undefined | YDKJS Book | Coding | Hard |
| 4 | The closure-in-a-loop bug, as code | YDKJS Book | Coding | Hard |
| 5 |
| createSpy — the test-double HOF |
| YDKJS Book |
| Coding |
| Hard |
| 6 | Multi-argument memoize (a Map trie) | YDKJS Book | Coding | Hard |