ES6 Spread and Butter in Depth (Ponyfoo)

convert a function's arguments into a real array with having to use apply or the arguments variable (Array.prototype.slice.call(arguments))

so instead of:

console.log.apply(console, [1, 2, 3])

// <- '1 2 3'

you can:

console.log(...[1, 2, 3])

// <- '1 2 3'

also works with nodeList

[...document.querySelectorAll('div')]

// <- [<div>, <div>, <div>]

concatenate two arrays:

[1, 2, ...more]

push an array into another one:

list.push(...[3, 4])

destructuring (ES6)

[a, ...rest] = list

define default values for variables

  function sum (left=1, right=2) {
  return left + right
}
console.log(sum())
// <- 3
console.log(sum(2))
// <- 4
console.log(sum(1, 0))
// <- 1

Abundancia