JavaScript: Hey Y’all Watch This! Caribbean Developers Conference 2019

Ah, JavaScript! Like it or not, it’s a “tragically important” language that is “eating the world.” Hate it? Love it? Avoid it? Embrace it?

This talk is a parade of face-palm JavaScript fails, history of JavaScript, why it is the way that it is, how it's getting better, and bad jokes sure to get an eye-roll from everyone! Along the way, we may even learn a few mistakes to avoid and tips to make our own JavaScript less terrible!

Transcript

33. > const lol = a + b + c – f * ( n + o ); NaN
34. > NaN >= 0 false
35. > NaN <= 0 false
36. > typeof NaN number
37. ( a + b ) + c !== a + ( b + c ) > 0.1 + 0.2 === 0.3 false
38. > 0.1 + 0.2 0.30000000000000004
39. > Math.round(0.4999999999999999722444243843710864894092082) 0 > Math.round(0.4999999999999999722444243843710864894092083) 1 I’ve got 99 problems but JavaScript ain’t 1.0000000000000009
40. > [ 2, 10 ].sort() [ 10, 2 ]
41. > ['10','10','10', '10', '10'].map( parseInt ) [ 10, NaN, 2, 3, 4 ]
42. > typeof undefined // undefined > typeof true // boolean > typeof "hello" // string > typeof 1 // number > typeof {lol:true} // object > typeof [1,2,3] // object > typeof null // object
43. > null == 0 // false > null > 0 // false > null < 0 // false > null >= 0 // true > null <= 0 // true > Number( null ) // 0
44. > false > null > undefined > "" > 0 > NaN
45. > wat.test("javascript"); // true > wat.test("wat r u doin"); // false > const wat = /a/g;
46. // undefined function troll() { return { haha: "ha!" }; } troll(); // automatic semi-colon
47. const arr = []; arr[1] = 1; arr[3] = 2; arr[10] = 3; arr.length // 11 arr[-1] = 4; arr.s = 5; arr.length // 11
48. const person = { name: "David", speak: function() { console.log( `${ this.name } likes bacon.` ); } }; person.speak(); // David likes bacon
49. const person = { name: "David", speak: function() { console.log( `${ this.name } likes bacon.` ); } }; const davidSpeak = person.speak; // true davidSpeak === person.speak; // undefined likes bacon davidSpeak();
50. this.name = "Mike"; const fatArrowPerson = { name: "Jerry", speak: () => { console.log( `${ this.name } likes bacon, too.` ); } }; // Mike likes bacon, too. fatArrowPerson.speak();
142. To boldly go where NaN has undefined before!
145. 1982 Sinclair ZX Spectrum Graphics Emulator
146. 1982 Sinclair ZX Spectrum Graphics Emulator
147. 1982 Sinclair ZX Spectrum Graphics Emulator
148. 1982 Sinclair ZX Spectrum Graphics Emulator
149. 1982 Sinclair ZX Spectrum Graphics Emulator
151. Johnny-Five
152. Remote Garage Opener
154. Ken Wheeler @ken_wheeler : The Crossbro
156. Ken Wheeler @ken_wheeler :
157. Cody Lundquist @codyglundquist : Band.js – Music Composer
158. Lucas Timmons @lucastimmons : Miley Cyrus Scraper
159. Charter.js – Chord and Number Charts
166. Mobile Apps Automation / DevOps Command Line (CLI) Services