bryzettler

const records = [
  { title: "The Clash", artist: "The Clash", type: "LP", lengthSec: 2220, released: "1977"},
  { title: "Rocket to Russia", artist: "Ramones", type: "LP", lengthSec: 1906, released: "1977"},
  ...etc
];

// es5
const way = records.reduce((acc, record) => {
  acc[`${record.title} - ${record.artist}`] = record;
  

bryzettler

const records = [
  { title: "The Clash", artist: "The Clash", type: "LP", lengthSec: 2220, released: "1977"},
  { title: "Rocket to Russia", artist: "Ramones", type: "LP", lengthSec: 1906, released: "1977"},
  ...etc
];

const wayOne = Object.assign({}, records);
const wayTwo = { ...records };
/* 
=> { 

bryzettler

// item is named record for easily knowing what
// we're operating on
records.reduce((acc, record) => {
  // Recored is not longer than 60 mins
  // return acc as is, doing nothing with record (filter)
  if (record.lengthSec > (60 * 60)) return acc;

  // Destructure acc into new array
  // Destructure record into new object and add display prop  
  return [

bryzettler

const records = [
  { title: "The Clash", artist: "The Clash", type: "LP", lengthSec: 2220, released: "1977"},
  { title: "Rocket to Russia", artist: "Ramones", type: "LP", lengthSec: 1906, released: "1977"},
  ...etc
];

records.filter(record => record.lengthSec > (60 * 60))
       .map(record => ({
         ...record,
         ['display']: `${record.artist} - ${record.title} (${record.released})`

bryzettler

// Takes an `array` a `callback` and an `initialValue`
// uses an inner `recursiveFn` to iterate over all array values
// calling the `callback` on each one
const reduce = (orgArray, callback, initialValue) => (
  (function recursiveFn(idx, acc) {
    // base condition to end looping    
    if (idx > orgArray.length - 1) return acc;
    // calculate and pass values to next step
    return recursiveFn(idx + 1, callback(acc, orgArray[idx], idx, orgArray))
    // start the iterations at orgArray[0] 

bryzettler