test power of map, filter and reduce

map-filter-reduce.js

const obj = [
  { time: "11:51", title: "Flexbox Video" },
  { time: "11:29", title: "Flexbox Video" },
  { time: "9:13",  title: "Flexbox Video" },
  { time: "8:22",  title: "Flexbox Video" },
  { time: "8:57",  title: "Flexbox Video" },
  { time: "7:12",  title: "Flexbox Video" },
  { time: "7:58",  title: "Redux Video" },
  { time: "7:24",  title: "Redux Video" },
  { time: "6:46",  title: "Flexbox Video" },
  { time: "5:23",  title: "Flexbox Video" },
  { time: "5:50",  title: "Flexbox Video" },
  { time: "5:52",  title: "Redux Video" },
  { time: "5:49",  title: "Flexbox Video" },
  { time: "5:17",  title: "Flexbox Video" },
  { time: "4:40",  title: "Flexbox Video" },
  { time: "4:45",  title: "Flexbox Video" },
  { time: "3:34",  title: "Redux Video" },
  { time: "5:59",  title: "Redux Video" },
  { time: "3:07",  title: "Flexbox Video" },
  { time: "3:31",  title: "Flexbox Video" }
];

let titles = obj.map(title => title.title);
let times  = obj.map(time => time.time);

let lolos = obj
  .filter(lolosTitles => lolosTitles.title.includes('Redux') )
  .map(lolosTimes => lolosTimes.time)
  .map(lolosConvertTimes =>{
    const parts = lolosConvertTimes.split(':').map(part => parseFloat(part));
    return (parts[0] * 60) + parts[1]
  })
  .reduce((runningTotal, seconds) => runningTotal + seconds);

console.log(lolos)