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

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33. > const lol = a + b + c – f * ( n + o );
    NaN
    

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34. > NaN >= 0
    false
    

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35. > NaN <= 0
    false
    

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36. > typeof NaN
    number
    

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37. ( a + b ) + c !== a + ( b + c )
    > 0.1 + 0.2 === 0.3
    false
    

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38. > 0.1 + 0.2
    0.30000000000000004
    

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39. > Math.round(0.4999999999999999722444243843710864894092082)
    0
    > Math.round(0.4999999999999999722444243843710864894092083)
    1
    I’ve got 99 problems but
    JavaScript ain’t
    1.0000000000000009
    

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40. > [ 2, 10 ].sort()
    [ 10, 2 ]
    

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41. > ['10','10','10', '10', '10'].map( parseInt )
    [ 10, NaN, 2, 3, 4 ]
    

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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
    

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43. > null == 0 // false
    > null > 0 // false
    > null < 0 // false
    > null >= 0 // true
    > null <= 0 // true
    > Number( null ) // 0
    

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44. > false
    > null
    > undefined
    > ""
    > 0
    > NaN
    

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45. > wat.test("javascript"); // true
    > wat.test("wat r u doin"); // false
    > const wat = /a/g;
    

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46. // undefined
    function troll() {
    return
    {
    haha: "ha!"
    };
    }
    troll();
    // automatic semi-colon
    

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47. const arr = [];
    arr[1] = 1;
    arr[3] = 2;
    arr[10] = 3;
    arr.length // 11
    arr[-1] = 4;
    arr.s = 5;
    arr.length // 11
    

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48. const person = {
    name: "David",
    speak: function() {
    console.log( `${ this.name } likes bacon.` );
    }
    };
    person.speak(); // David likes bacon
    

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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();
    

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50. this.name = "Mike";
    const fatArrowPerson = {
    name: "Jerry",
    speak: () => {
    console.log( `${ this.name } likes bacon, too.` );
    }
    };
    // Mike likes bacon, too.
    fatArrowPerson.speak();
    

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142. To boldly go where NaN has
     undefined before!
     

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145. 1982 Sinclair ZX Spectrum
     Graphics Emulator
     

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146. 1982 Sinclair ZX Spectrum
     Graphics Emulator
     

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147. 1982 Sinclair ZX Spectrum
     Graphics Emulator
     

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148. 1982 Sinclair ZX Spectrum
     Graphics Emulator
     

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149. 1982 Sinclair ZX Spectrum
     Graphics Emulator
     

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151. Johnny-Five
     

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152. Remote Garage Opener
     

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154. Ken Wheeler @ken_wheeler :
     The Crossbro
     

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156. Ken Wheeler @ken_wheeler :
     

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157. Cody Lundquist @codyglundquist :
     Band.js – Music Composer
     

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158. Lucas Timmons @lucastimmons :
     Miley Cyrus Scraper
     

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159. Charter.js – Chord and Number Charts
     

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166. Mobile Apps
     Automation / DevOps
     Command Line (CLI)
     Services
     

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