language-features

default parameters
template literals
destructuring assignment
arrow functions
promises
block-scoped variable declarations
classes
modules
async/await
decorators
the exponent operator
String.prototype.padStart
symbols
object spread
observables
Object.values
generators
getters and setters
WeakMap
proxies
dynamic import
pattern matching
partial application
closures
hoisting
media queries
machine learning
the blockchain
prototypal inheritance
Date.now()
case sensitivity
automatic semicolon insertion
dynamic types
static typing
for/of loops
the with statement
"use strict"
just-in-time compilation
variadic functions
array comprehensions
functions as first-class citizens
rest parameters
shorthand method definition syntax
sparse arrays
regular expressions
eval
immediately-invoked function expressions
syntax errors
tail-call optimised recursive functions
loops