Javascript

• Created in 10 days (May 1995)
  • Brendan Eich
• ECMA for standartisation
• ECMAScript 3 in 1998
• Browser wars

Dumb language to make something blink on the web page..

Javascript

• Ajax: A New Approach to Web Applications
  • ​February 2005
• Javascript libraries/frameworks

• ECMAScript 5, early 2009

• Node.js, 2009

Javascript

Javascript

Javascript, Javascript everywhere..

• Rapid community growth
• Tools, IDE support, debuggers
• Frameworks and SPAs

Javascript

• ECMAScript 6, June 2015
• Lots of new language features

Let + Const

• Block-scoped binding
• let is the new var
• const is single assignment only

Arrow functions

• Function shorthand using => syntax
• Statement block body
  • a => { return a + 1; }
• Expression block body
  • a => a - 1
• Share same lexical this as surrounding code

Classes

• Syntactic sugar
• Easier to use (?)
• Prototype-based inheritance
• super()
• Instance and static methods
• Constructor

Enhanced object literals

• Prototype at construction
• Shorthand assignments
• Methods and super() calls
• Computed property names

Template strings

• Syntactic sugar
• Basic literal strings
• Multiline strings
• String interpolation

Destructuring

• Binding variables
• Supports arrays and objects
• Fail-soft - undefined if fails

Default + Rest + Spread

• Default parameter value
• Array to consecutive arguments
• Trailing parameters to array

Modules

• Language level support

Promises

• Async programming
• Language level support

New built-in methods

• Object.assign
• String.startsWith/endsWith
• String.includes/repeat
• Array.find/findIndex
• Array.keys/values/entries