JavaScript's Type Conversion: A Horror Story

Content Replace a semicolon (; with a greek question mark (;) in your friend's JavaScript and watch them pull their hair out over the syntax error. error: unknown start of token: u37e - main.rs:2:30 2 I printin! ("Hello, world!"); help: Unicode character ';' (Greek Question Mark) Looks like ';' (Semicolon), but it is not printin! ("Hello, world!"); Pathetic.

Content PROBLEM: JAVASCRIPT HAS ALMOST NO STANDARD LIBRARY SOLUTION: THOUSANDS OF COMMUNITY -SUPPORTED LIBRARIES OF WILDLY VARYING QUALITY PROBLEM: JAVASCRIPT HAS NO PACKAGING OR A LINKER TO TIE THESE PACKAGES TOGETHER PROBLEM: JAVASCRIPT WON'T RUN OUTSIDE THE BROWSER SOLUTION: V8 PROBLEM: JAVASCRIPT IS SINGLE -THREAD BY DESIGN SOLUTION: ASYNCHRONOUS PROGRAMMING, NODE. JS PROBLEM: CALLBACK HELL PROBLEM: PROTOTYPAL INHERITANCE IS PANTS -ON- HEAD STUPID THAT'S RIGHT, I SAID IT. PROBLEM: WEB RESOURCES NEED TO BE MINIFIED AND ZIPPED FOR PERFORMANCE PROBLEM: THE DOM IS TOO SLOW FOR VIDEO GAMES SOLUTION: CANVAS PROBLEM: JAVASCRIPT IS TOO SLOW FOR VIDEO GAMES SOLUTION: USE AN ASSEMBLY- LIKE SUBSET OF JAVASCRIPT CALLED ASM.JS PROBLEM: ASM.JS IS BASICALLY UNWRITABLE 4 HUMANS. SOLUTION: COMPILE A BETTER LANGUAGE TO JAVASCRIPT (C, EMASCRIPT 2016, COFFEESCRIPT, JSX) SOLUTION: HUNDREDS OF COMMUNITY SUPPORTED BUILD TOOLS OF WILDLY VARYING QUALITY PROBLEM: GRUNT. SOLUTION: GULP PROBLEM: GULP PROBLEM: MACHINE GENERATED OUTPUT IS MORE DIFFICULT TO DEBUG PROBLEM: ASYNC IS STILL A NIGHTMARE, HUH? PROBLEM: BALLOONING PROJECT SIZE AND COMPLEXITY PROBLEM: JAVASCRIPT STILL DOESN'T DO EVERYTHING PROBLEM: OUTPUT RUNS VERY SLOWLY ON MOBILE DEVICES SOLUTION: ELECTRON, PHONEGAP, FIREFOXOS HOW IS DIGGING GOING TO GET US OUT OF THIS HOLE? WHERE I AM FROM, THE POINT OF DIGGING IS NOT FREEDOM FROM DIGGING

Content Marko 4 Denic denicmarko STOP making fun of different programming languages C is FAST Java is POPULAR Ruby is COOL Python is BEAUTIFUL PHP JavaScript is AWESOME Haskell is INTRIGUING 17:12 07 May 20 Twitter Web App

Content People learning JavaScript: "I'II use array.sort) to sort this list of numbers!" JavaScript: 11, 100000, 24, 30, 4

The classic "age is just a number" platitude gets a perfect programmer's twist. In JavaScript and many other languages, what looks like a number is often silently converted to a string when you least expect it. That smug face in the third panel is every backend dev who's spent hours debugging why 18 + 1 = 181 instead of 19 . Type coercion: ruining perfectly good calculations since 1995.

Content What users see via frontend What dev see via backend Frontend Backend