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
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
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