extra-array-methods-challenges.js

// ***************************************************************
// MAP: Calculate the final grade for each student in the list below.
// Grade our students based on their performance on two projects (40% of final grade)
// and their final exam (60% of final grade).
// ***************************************************************

const students = [
  {
    name: 'Tony Parker',
    firstProject: 80,
    secondProject: 75,
    finalExam: 90
  },
  {
    name: 'Marc Barchini',
    firstProject: 84,
    secondProject: 65,
    finalExam: 65
  },
  {
    name: 'Claudia Lopez',
    firstProject: 45,
    secondProject: 95,
    finalExam: 99
  }
];

const finalList = students.map(student => {
  // console.log(student);
  const projAvg = (student.firstProject + student.secondProject) / 2;

  const finalGrade = projAvg * 0.4 + student.finalExam * 0.6;
  const updStudent = {
    name: student.name,
    finalGrade: Math.round(finalGrade)
  };
  return updStudent;
});

console.log(finalList);

// [
//   { name: 'Tony Parker', finalGrade: 85 },
//   { name: 'Marc Barchini', finalGrade: 69 },
//   { name: 'Claudia Lopez', finalGrade: 87 }
// ]


// REDUCE: Calculate the average rate

const product = {
  name: 'AmazonBasics Apple Certified Lightning to USB Cable',
  price: 7.99,
  manufacter: 'Amazon',
  reviews: [
    {
      user: 'Pavel Nedved',
      comments: 'It was really usefull, strongly recommended',
      rate: 4
    },
    { user: 'Alvaro Trezeguet', comments: 'It lasted 2 days', rate: 1 },
    { user: 'David Recoba', comments: 'Awesome', rate: 5 },
    { user: 'Jose Romero', comments: 'Good value for money', rate: 4 },
    { user: 'Antonio Cano', comments: 'It broked really fast', rate: 2 }
  ]
};

const sumRate = product.reviews.reduce((acc, currValue) => acc + currValue.rate, 0);
const avgRate = sumRate / product.reviews.length;

console.log(avgRate); // => 3.2


// FILTER

// Challenge 1:

// 1. In the given array, find the elements that start with "m" and make them capitalized.
// 2. Bonus: If the city name has two or more names, make them both capitalized (ex. Mexico City).

const cities1 = ["miami", "barcelona", "madrid", "amsterdam", "berlin", "sao paulo", "lisbon", "mexico city", "paris"];

const capsMs = cities1.filter(theCity => theCity[0] === "m")
                      .map(city => {
                        if (city.includes(" ")){
                          let splitted = city.split(" ");
                          const len = splitted.length;
                          for (let i = 0; i < len; i++){
                            splitted[i] = splitted[i][0].toUpperCase() + splitted[i].slice(1);
                          }
                          return splitted.join(" ");
                        }
                        return city[0].toUpperCase() + city.slice(1)
                      })

console.log(capsMs);

// SORT
// Sort the following array of objects by title value: [source-w3resource](https://www.w3resource.com/javascript-exercises/javascript-array-exercise-25.php)

const library = [
  { author: 'Bill Gates', title: 'The Road Ahead', libraryID: 1254 },
  { author: 'Steve Jobs', title: 'Walter Isaacson', libraryID: 4264 },
  {
    author: 'Suzanne Collins',
    title: 'Mockingjay: The Final Book of The Hunger Games',
    libraryID: 3245
  }
];

function compareToSort(x, y) {
  if (x.title < y.title) return -1;
  if (x.title > y.title) return 1;
  return 0;
}

console.log(library.slice().sort(compareToSort));

// [ { author: 'Suzanne Collins',
  //   title: 'Mockingjay: The Final Book of The Hunger Games',
  //   libraryID: 3245 },
  // { author: 'Bill Gates',
  //   title: 'The Road Ahead',
  //   libraryID: 1254 },
  // { author: 'Steve Jobs',
  //   title: 'Walter Isaacson',
  //   libraryID: 4264 } ]