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Episode 4 of 9 · The interview course

JavaScript interview: the event loop, promises and async await

Chapters

1. The question you get asked0:00
2. Single threaded, precisely0:15
3. Async is not another thread0:33
4. The picture to draw on a board0:50
5. The call stack1:05
6. One full journey1:20
7. The loop asks one question1:37
8. Blocking the page1:51
9. Why a delay of zero is not zero2:05
10. What a callback is2:21
11. The pyramid of doom2:36
12. Error first callbacks2:51
13. Inversion of control3:06
14. The three states3:22
15. How that fixes the real bug3:37
16. Then, catch and finally3:54
17. Returning a value or a promise4:10
18. Where the catch goes4:26
19. The promise constructor smell4:43
20. Promise.all5:00
21. AllSettled5:14
22. Race and any5:31
23. Async await is sugar5:48
24. Two rules asked directly6:04
25. The two second slowdown6:21
26. Start both, then wait6:36
27. Two queues6:52
28. The drain rule7:07
29. The canonical puzzle7:24
30. The answer7:39
31. A promise inside a timeout7:54
32. Code after await is a microtask8:09
33. Trace the whole thing8:27
34. QueueMicrotask8:42
35. For await of8:59
36. Starving the loop9:14
37. NextTick and setImmediate9:31
38. The error you never see9:48
39. ForEach does not await10:07
40. Publish and subscribe10:24
41. Writing on and emit10:40
42. Off and once10:53
43. Where you have already used it11:09
44. Debounce11:22
45. Throttle11:39
46. The race on every keystroke11:53
47. AbortController12:10
48. Interval drift12:27
49. Animation frames12:42
50. Non blocking input output12:58
51. What await is built on13:15
52. The one rule13:30

JavaScript interview: the event loop, promises and async await. Two days before a JavaScript interview, this is the area you get asked about. Not closures. The event loop, promises, async await. It is the part you cannot fake. They ask what thi

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