Teaching Functions

teaching_functions.js

function greet(name, day, special) {
  // your code here
}
greet('Robert', 'Tuesday', 'fried catfish'); // This should return the String "Hello, Robert. Today is Tuesday, and the special is fried catfish."

// ==========================================================

function sumOf(numbers) {
  // your code here
}
sumOf([27, 312, 91]); // This should return the sum of the numbers passed via the array

// ==========================================================

function averageOf(numbers) {
  // your code here
}
averageOf([1, 2]); // This should return the average of the numbers passed via the array.

// ==========================================================

function calculateStatistics(scores) {
  // your code here
}
var statistics = calculateStatistics([5, 3, 100, 3, 9]); // This should return an object with keys `min`, `max` and `sum`
statistics.min // => 3
statistics.max // => 100
statistics.sum // => 120

// ==========================================================

var songs = [
  {
    id: 1,
    title: "Mother",
    author: "Pink Floyd",
    album: "The Wall"
  },
  {
    id: 2,
    title: "Since I've been Loving You",
    author: "Led Zeppelin",
    album: "Led Zeppelin III"
  },
  {
    id: 3,
    title: "Re: Stacks",
    author: "Bon Iver",
    album: "For Emma, Forever Ago"
  },
  {
    id: 4,
    title: "Von",
    author: "Sigur Rós",
    album: "Hvarf-Heim"
  }
];
var idsAndTitles = [];

// Use forEach to create objects containing only `id` and `title` for each song.
// Place each of these objects into the `idsAndTitles` array using Array's push() method.
// This should return something like [{ id: 1, title: "Foo" }, { id: 2, title: "Bar" }]
// your code here

// ==========================================================

Array.prototype.mapIt = function(callback) {
  var results = [];
  this.forEach(function(itemInArray) {
    // your code here
  });
  return results;
};

songs.mapIt(function(song) {
  return { id: song.id, title: song.title };
}); // Should return something like [{ id: 1, title: "Foo" }, { id: 2, title: "Bar" }]