Javascript Objects, Methods

Actions are functions in properties
Arrow functions have no this

let B = {
  age: 20,
  sayHi() { let a = () => this.age }

Arrow

Javascript Fundamentals, Functions

Functions has full access to an outer variable
We can create functions using function expression 

let a = 1
function hello() {
  let sum = (b,c) => a+b+c
  sum(2,3) == 6

Function, Arrow

Php Versions, 7.4

Typed properties, starting with PHP 7.4
Arrow functions, PHP 7,4

declare(strict_types=1)
class
    String ?$name
    function set($x) : void

Arrow, Strict

Java Lambdas, Expressions

Annonimous inner classes
Lambdas, pass behavior not objects

button.addActionListener
  new ActionListener
    op = (x, y) -> x + y

Arrow