Javascript Event Loop

Course Progress

1. 1

   Synchronous Execution

   What is the output order of simple synchronous code?

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2. 2

   setTimeout Basics

   How does setTimeout affect execution order?

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3. 3

   Promise Basics

   How do promises affect the event loop? Let's say we make a successful call to some API in the cloud. This is typically asynchronous. In what order will this code be executed?

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4. 4

   setTimeout vs Promise

   Which comes first: microtasks or macrotasks (a.k.a. tasks)?

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5. 5

   Multiple Promises

   How are multiple .then() callbacks ordered?

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6. 6

   Nested setTimeout

   What happens with nested setTimeout calls?

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7. 7

   Promise in setTimeout

   How do promises inside setTimeout behave?

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8. 8

   setTimeout in Promise

   How does setTimeout inside a promise behave?

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9. 9

   Async/Await Basics

   How does async/await affect execution order?

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10. 10

    Multiple Awaits

    What happens with multiple awaits?

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11. 11

    Promise Chain

    How does chaining .then() affect order?

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12. 12

    Error in Promise

    How are errors in promises handled?

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13. 13

    process.nextTick

    How does process.nextTick fit in the event loop?

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14. 14

    queueMicrotask

    How does queueMicrotask compare to Promise and setTimeout?

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15. 15

    setImmediate

    How does setImmediate fit in the event loop?

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16. 16

    Multiple Microtasks

    How are multiple microtasks ordered?

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17. 17

    Non-awaited promises

    What is the order of non-awaited functions with awaited functions inside of them?

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18. 18

    Await the first but not the second promise

    What happens if you await the first async function (the promise) and not the other one?

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19. 19

    Await the first long running fetch

    What if the first awaited function has a long running fetch inside of it?

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20. 20

    Await the second, fast running fetch

    What if the first not-awaited function has a long running fetch inside of it and you await only the second?

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21. 21

    Async Error Handling chaining

    How are errors handled in when not awaited?

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22. 22

    Awaited Async Error Handling

    How are errors handled in when awaited?

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23. 23

    Send meny requests at once?

    What if you want to do many asynchronous operations at once?

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24. 24

    Race asynchronous operations

    What happens in a race between two asynchronous operations?

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25. 25

    How do you call asynchronous operations after each other?

    What if you want to call asynchronous functions in sequence?

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26. 26

    How do you call asynchronous operations after each other, with await?

    What if you want to call asynchronous functions in sequence, with await?

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27. 27

    How does a javascript generator work?

    How does an async generator work and how is the program executed?

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28. 28

    How does an async generator yield values with an await inside?

    How does an async generator yield values, what if you await inside the generator? The closure is a bonus ;)

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29. 29

    nextTick vs. setImmediate?

    Which one is run first, nextTick or setImmediate?

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30. 30

    When do you need await?

    How does await affect the output of asynchronous functions? Can you tell which console.log writes A and which writes the unfulfilled promise, i.e. [object Promise]?

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31. 31

    What about the other way around?

    Same thing again but notice the swap of the await. Can you tell which console.log writes A and which writes the unfulfilled promise, i.e. [object Promise]?

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32. 32

    Let's put your knowledge to the test

    Can you predict the output order? If you can do it right away we know you have succeeded in learning the event loop!

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33. 33

    One more tough one, can you solve it?

    Let's put your skills to the test, solve it one go!

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