Tinusw

a = [1,2,[3,4,[5,6,[7,8]]]]
b = [9, 10]

function flatten() {
  let new_arr = []
  for(let i=0; i < arguments.length  ; i++){
    new_arr = new_arr.concat(arguments[i])
  }
  return new_arr.reduce(function (flattened_arr, j) {
      return j instanceof Array ? flattened_arr.concat(flatten(j)) : flattened_arr.concat(j);

Tinusw

function flatten(a) {
  if (a instanceof Array) {
    return a.reduce((flat, i) => {
      if (i instanceof Array) {
        return flat.concat(flatten(i));
      }
      return flat.concat(i);
    }, []);
  }
  return a;

Tinusw

var a = [1,2,3,4,[5,6,7]]
var b = [8,9,10]

function flatten() {
  var new_arr = []
  for(i=0; i < arguments.length - 1 ; i++){
    for(j=0; j < arguments[i].length; j++){
      if(arguments[i][j] instanceof Array){
        new_arr = new_arr.push(flatten(arguments[i][j]))
      } else {

Tinusw

let a = [1,2,3,4,5]
let b = [1,2,3,4,5]

function flatten() {
  var new_arr = []
  for(i=0; i < arguments.length; i++){
    new_arr = new_arr.concat(arguments[i])
  }
  return new_arr
}

Tinusw

function add(arg1){
  return function(arg2) {
    return arg1 + arg2
  }
}

add(2)(3)
// 5

Tinusw

function add(arg1){
  // intermediate variable   
  let first_execution = arg1
  return function(arg2) {
    return first_execution + arg2
  }
}

add(2)(3)
// 5

Tinusw

add(2, 5); // 7
add(2)(5); // 7

Tinusw

for(i=0; i <= 100; i++){
  console.log((i % 3 ? '' : 'fizz') + (i % 5 ? '' : 'buzz') || i)
}

Tinusw

for(i = 0; i <= 100; i++){
  let output = ''
  if(i % 3 === 0){
    output+='fizz'
  }
  if(i % 5 === 0){
    output+='buzz'
  }
  if(output === ''){
    output+=i

Tinusw

for(i=0; i <= 100; i++){
  if (i % 3 === 0 && i % 5 === 0){
   console.log('fizzbuzz')
  } else if (i % 3 === 0){
    console.log('fizz')
  } else if (i % 5 === 0){
    console.log('buzz')
  } else {
    console.log(i)
  }