Even Rubber Duck knows JS better than you!

Transcript

1. Even Rubber Duck knows JavaScript better than you! by Nikita

   Galkin Sep 8, 2018

2. Bug on line 7 Quack Quack

3. Your code is sucks Quack Quack

4. None

5. class Employee { constructor(role) { this.role = role; } get

   mainResponsibility() { switch (this.role) { case 'Developer': return 'Write Code'; ...

6. Turn and Write Code

7. 7 Hiring process 1. HR-interview 2. CV-screening 3. Technical interview

   4. Interview with the client Dev Team

8. Upgraded Hiring process 1. HR-interview 2. CV-screening 3. Live coding

   as fail fast check 4. Technical interview 5. Test task as second chance 6. Interview with the client 8

9. Live coding • 20 minutes only • Remote via skype

   with screen-sharing • Without bla-bla bullshit • 4-6 trivial JS tasks at JSfiddle • Easy to see does the code work or not • Googling or Asking is okey 9

10. Expectations Reality VS

11. None

12. You lost context Quack

13. const obj = { fullname: 'Yellow Duck', getFullname: function() {

    return this.fullname; } }; const nameGetter = obj.getFullname; // @todo fix this line document.getElementById('name').innerHTML = nameGetter();

14. const obj = { fullname: 'Yellow Duck', getFullname: function() {

    return this.fullname; } }; const nameGetter = obj.getFullname; // @todo fix this line document.getElementById('name').innerHTML = obj.fullname;

15. const fullname = 'Yellow Duck'; const obj = { getFullname:

    function() { return fullname; } }; const nameGetter = obj.getFullname; // @todo fix this line document.getElementById('name').innerHTML = nameGetter();

16. const obj = { fullname: 'Yellow Duck', getFullname: function() {

    return this.fullname; } }; const nameGetter = obj.getFullname.bind(obj); document.getElementById('name').innerHTML = nameGetter();

17. 17

18. Just return new promise Quack Quack

19. function wait(timeout) { // @todo implement } wait(1000) .then(() =>

    { document.getElementById('answer').innerHTML = 'Done!'; });

20. function wait(timeout) { return { then: function(callback) { callback(); }

    } } wait(1000) .then(() => { document.getElementById('answer').innerHTML = 'Done!'; });

21. function wait(timeout) { setTimeout(function() {}, timeout); } wait(1000) .then(() =>

    { document.getElementById('answer').innerHTML = 'Done!'; });

22. function wait(timeout) { setTimeout(function() { return Promise(); }, timeout); }

    wait(1000) .then(() => { document.getElementById('answer').innerHTML = 'Done!'; });

23. Release the Quacken!

24. function wait(timeout) { return new Promise(r => setTimeout(r, timeout)); }

    wait(1000) .then(() => { document.getElementById('answer').innerHTML = 'Done!'; });

25. Use data structure Quack Quack

26. const unfiltered = [1, 2, 3, 5, 1, 5, 9,

    1, 2, 8]; const filtered = removeDuplicates(unfiltered); // filtered should be equal [1, 2, 3, 5, 9, 8] document.getElementById('answer').innerHTML = filtered; function removeDuplicates(arr) { // @todo implement }

27. const unfiltered = [1, 2, 3, 5, 1, 5, 9,

    1, 2, 8]; const filtered = removeDuplicates(unfiltered); // filtered should be equal [1, 2, 3, 5, 9, 8] document.getElementById('answer').innerHTML = filtered; function removeDuplicates(arr) { return arr.filter(...) }

28. Ducks win!

29. const unfiltered = [1, 2, 3, 5, 1, 5, 9,

    1, 2, 8]; const filtered = removeDuplicates(unfiltered); // should be [1, 2, 3, 5, 9, 8] document.getElementById('answer').innerHTML = filtered; function removeDuplicates(arr) { const obj = {}; for (const el of arr) { obj[el] = true; } return Object.keys(obj); }

30. 30 Googling is better, than learning JS

31. const unfiltered = [1, 2, 3, 5, 1, 5, 9,

    1, 2, 8]; const filtered = removeDuplicates(unfiltered); // filtered should be equal [1, 2, 3, 5, 9, 8] document.getElementById('answer').innerHTML = filtered; function removeDuplicates(arr) { return Array.from(new Set(arr)); }

32. 32 HAPPY CODING WITH JAVASCRIPT! You can find me at

    twitter as @galk_in Slides are available at speakerdeck.com/galkin or at my site galk.in