The document discusses the history and evolution of JavaScript over time. It began as a language created in 10 days by Brendan Eich in 1995. While initially misunderstood and fragmented across browsers, JavaScript has adapted and survived through open source contributions, a changing web, and maturation of the industry. The language is constantly evolving in unpredictable ways to shoot out in new directions. Its adaptability is key to its survival, and continued change will help ensure it does not stagnate. There is no single definition of JavaScript due to its ubiquity and ability to evolve.

1. There Is No
JavaScript
Noam Kfir
Senior Architect, Sela Group
http://noam.kfir.cc
@NoamKfir

2. A Brief History of JavaScript

3. The Bubbling Pool
Brendan Eich hacked JavaScript together in ten
days

4. The First Decade Happened
• JavaScript was handed to a committee
• The browsers went to war
• A bunch of languages fought and JavaScript
won
• The web got big

5. The Mesozoic Lair
John Resig raised JavaScript out of the swamp

6. The Second Decade Happened
• IE6 died a slow painful death
• We got standards and frameworks and tools
• JavaScript spread to Node.js and MongoDB and
Johnny Five!

7. And Then Things Got Weird

8. But First, A Little Exercise!
Yes, we’re going to get physical…

9. Nod Your Head
if you use JavaScript

10. Clap Your Hands
if you love JavaScript

11. Pound Your Feet
if you hate JavaScript

12. Real Programmers Multi-Task
Use it. Love it. Hate it.
Nod. Clap. Pound.
But why?

13. Let’s Ask Expert!
Douglas Crockford, 2001
“JavaScript is the world’s
most misunderstood
programming language.”
The

14. Most Misunderstood
• the name carries misleading implications
• typecasting and lisp in c’s clothing
• moving target and design errors
• amateurs and lousy implementations
• bad books and a substandard standard
• not really object-oriented?

15. But Not Anymore
• Crockford was right, but things have changed
• JavaScript is no longer misunderstood
• So the question remains… Why?

16. Typology

17. Dynamic?
Yes

18. Weakly Typed?
Yup
Except it also has a few strong types

19. Compiled?
Of course not
Except that all major JavaScript engines
perform JIT (and AOT?) compilation today
Or maybe even grunt and gulp and webpack?

20. Interpreted?
Definitely!
Actually, interpreted semantics
Which change under strict mode
And again for ES6

21. Functional?
Yes… high-order functions
And no… side effects and immutable semantics
Unless ES5: filter, map, reduce, some,
defineProperty…
Or ES6: consts, arrow functions, destructuring,
generators…
Or ES7: async, observe…

22. Inheritance?
Absolutely, but it’s weird
Prototypes, not classes
Except in ES6, where classes are actually
prototypes
Or the gazillion logical class implementations,
which are mostly abstractions for prototypes or
glorified mixins

23. Modules?
Nope, not really
Unless you use specific design patterns
Or hacks, like immediate functions
Or a framework that rolls its own, like Angular
Or AMD (RequireJS)
Or CommonJS (Node.js)
Or ES6 modules

24. Expressive?
It really depends on who you ask
But before jQuery showed us the way, most
programmers did not see it as expressive or use
it that way

25. So JavaScript Is…
• Clearly dynamic
• Mostly weakly typed
• Kind of interpreted yet also compiled
• Trending toward but not quite functional
• Inherently mixed up about inheritance
• Inconsistently modular
• Subjectively expressive

26. WTF?!!!!
JavaScript is no longer misunderstood…
But it is confusing
JavaScript is a buffet!

27. Coping Strategies

28. The Ostrich
Ignore JavaScript
“We don’t need no stinkin’ JavaScript!”
• Go native
• Or stick to the server
• … And curse Brendan Eich

29. The Chameleon
Hide JavaScript
“the assembly language of the web”
• JavaScript is ugly
• So compile familiar
languages “down”
• Or invent “prettier”
languages to transpile

30. The Phoenix
Reinvent JavaScript
“The king is dead. Long live the king.”
• Improve JavaScript gradually
• Or drastically
• Or create a “better” superset

31. The Kangaroo
Skip Over JavaScript
“cut out the middleman”
• Use an alternative in the browser
(like Dart or VBScript)
• Or go binary (with WebAssembly)

32. The Dinosaur
Stop Changing JavaScript
“Why ruin a good thing?”
• It works, leave it alone
• The advantage of living
in the past is that it’s
all documented

33. Coping Strategies
• The Ostrich: ignore JavaScript
• The Chameleon: hide JavaScript
• The Phoenix: reinvent JavaScript
• The Kangaroo: skip over JavaScript
• The Dinosaur: stop changing JavaScript

34. There Seems to Be a Pattern
And it’s not the animals

35. Hint #1 – The Environment
In which environments does your JavaScript run?
• In the browser?
• On the server?
• In the database?
• On some device?
• Everywhere?

36. Hint #2 – The Ecosystem
What language do you use to write your code?
• JavaScript all the way!
• CoffeeScript?
• TypeScript or Flow?
• C# or Java?
• Anything but JavaScript?

37. Hint #3 – The Language
Which JavaScript do you actually use?
• ES3?
• ES5?
• ES6?
• Some other version?
• Do you even know?

38. Hint #4 – The Style
Do you have a preferred programming style?
• More functional?
• More object-oriented?
• Whatever the framework prescribes?
• Whatever gets the job done?
• What are you talking about?

39. The Problem
• JavaScript is ubiquitous, flexible, feature-rich,
expressive and popular
• But it is also very confusing and
suffering from an identity crisis

40. Converging and Diverging
• JavaScript engines are finally converging and
are achieving remarkable feature parity,
implying eventual consistency across tools,
platforms and ecosystems
• But the tools, platforms and ecosystems are
actually diverging, despite expectations
• These are opposing trends

41. Has JavaScript Peaked?
• JavaScript does not seem to be slowing down
• But neither is the fragmentation
• These are opposing trends

42. JavaScript Has Evolved
• JavaScript’s design has been influenced by
many factors and contradictory goals:
• open source
• competing browsers
• a changing web
• maturation of the industry
• etc.
• They have caused fragmentation
• But ironically, they have also contributed to its
evolution and survival

43. JavaScript Is Inherently Adaptive
• The key to its survival is its adaptability
• Its ubiquity and strange typology are
evolutionary byproducts
• Change is part of its DNA
• The language will continue to evolve

44. Looking Forward
• JavaScript is constantly shooting
out in new directions
• It will hopefully never stabilize
• Stabilization will be its death knell
• Change makes our lives difficult
• In the long run, it’s a necessity

45. There Is No Spoon
• Do not try and bend the spoon. That’s
impossible. Instead, only try and realize the
truth.
• What truth?
• There is no spoon.
• There is no spoon?
• Then you’ll see that it is not the spoon that
bends, it is only yourself.

46. Thank You
Noam Kfir
Senior Architect, Sela Group
http://noam.kfir.cc
@NoamKfir