jafow

/** Write a function `combo` that takes two parameters--fn1, fn2--and returns a function. 
* combo should combine the two function parameters and invoke them on any values passed as arguments
* ex: 
* var add2 = (n) => n + 2;
* var times3 = (n) => n * 3;
* var plus2AndMultiply3 = combo(add2, times/3)
* plus2AndMulitply3(5) // --> 17
*/
// Function composition in Es6
const combo = (fn1, fn2) => (...args) => fn1(fn2(args));

jafow

// define a function 'targetSum' that takes 2 arguments, an array and a target number, and returns a boolean for whether or not 
//2 values in the array sum up to the target number
// ex: targetSum([1, 3, 5, 0, 6, 4, 2], 11) // => 11

// brute force 
function targetSum (arr, target) {
  for (var i = 0; i < arr.length; i++) {
    for (var j = i + 1; j < arr.length; j++) {
      if (arr[i] + arr[j] === target) return true
    }

jafow

class Row extends Component {
  // this component receives props and extends it with color and effect. `super()` keyword permits us to use `this`
  constructor(props) {
    super(props)
    this.color = 'blue'
    this.effect = 'wow'
  }

  render () {
    return (

jafow

var presidentialPollingData = [{"pollster":"RCP Average","date":"6/27","clinton":45,"trump":39},
{"pollster":"Quinnipiac","date":"6/27","clinton":42,"trump":40},{"pollster":"ABC News/Wash Post","date":"6/23","clinton":51,"trump":39},
{"pollster":"NBC News/Wall St. Jrnl","date":"6/23","clinton":46,"trump":41},{"pollster":"Rasmussen Reports","date":"6/21","clinton":44,"trump":39},
{"pollster":"Reuters/Ipsos","date":"6/22","clinton":44,"trump":34},{"pollster":"Economist/YouGov","date":"6/20","clinton":43,"trump":39},
{"pollster":"CNN/ORC","date":"6/19","clinton":47,"trump":42},{"pollster":"Gravis","date":"6/16","clinton":51,"trump":49},
{"pollster":"Monmouth","date":"6/19","clinton":49,"trump":41},{"pollster":"Rasmussen Reports","date":"6/15","clinton":44,"trump":39},
{"pollster":"Reuters/Ipsos","date":"6/15","clinton":41,"trump":32},{"pollster":"CNBC","date":"6/13","clinton":40,"trump":35},
{"pollster":"Bloomberg*","date":"6/13","clinton":49,"trump":37},{"pollster":"CBS News","date":"6/13","clinton":43,"trump":

jafow

[user]  name = jafow
email = jared.a.fowler@gmail.com

[credential]
helper = cache
help = cache --timeout 1800
[core]
autocrlf = input
safecrlf = true
editor = vim

jafow

/**
 * divorce takes an array of nested array pairs and returns 2 one-dimensional arrays with elements from each pair, in order
 * ex: divorce([[1,2], [3,4]]) --> {a1: [1,3], a2: [2,4]}
 */
const divorce = (arr, a1 = [], a2 = []) =>
    !arr[0]
    ? { a1, a2 }
    : divorce(arr.slice(1), a1.concat(arr[0][0]), a2.concat(arr[0][1]))

jafow

/**
 * input: @arr array
 *        @out array
 *        @cycles integer
 * output: @out, array of @cycles repetions of @arr
 * ex: cartwheel([1,2,3], 3) --> [1,2,3,1,2,3,1,2,3]
 */
 
 const cartwheel = (arr, out = [], cycles) => 
    cycles === 0

jafow

// Write a fn `getLength` that takes one argument, an array, and returns the length of that array. 
// getLength should be written without using the built-in .length() method, and without any `for` or `while` loops.

const getLength = ([first, ...rest], len = 0) => 
  !first
  ? len
  : getLength(rest, len + 1)


// ES5

jafow

function delay (fn, wait) {
  var args = Array.prototype.slice.call(arguments, 2)
  setTimeout(function () {
    return fn.apply(this, args)
  }, wait)
}

// with ES6 rest operator instead of slicing arguments object 
const delay2 = (fn, wait, ...args) => {
  setTimeout(() => fn.apply(this, args), wait)

jafow

/** Once takes a function as an argument and returns a function or undefined, depending on whether the fn passed as an argument 
* has been called. If that function hasn't been invoked, Once will return the value of that function applied to any arguments. 
* otherwise it will return undefined. 
*/

// implementation #1
function once (fn) {
  var run = false
  return function () {
    if (run) return void 0