JS Challenge mod 4

js-challenge-1.md

Prompt

Extend the native Array data type to allow a groupBy method so that when given an array of objects, you can group each array item by a specified property.

For example, given an array of Turing students:

let students = [
  { name: "Louisa", module: "4FE", track: "frontEnd" },
  { name: "Nathaniel", module: "3FE", track: "frontEnd" },
  { name: "Robbie", module: "3BE", track: "backEnd" },
  { name: "Brenna", module: "4FE", track: "frontEnd" },
  { name: "Brittany", module: "2BE", track: "backEnd" },
  { name: "Taylor", module: "3BE", track: "backEnd" }
];

Calling:

students.groupBy('track');

Will return:

{
  frontEnd: [
    { name: "Louisa", module: "4FE", track: "frontEnd" },
    { name: "Nathaniel", module: "3FE", track: "frontEnd" },
    { name: "Brenna", module: "4FE", track: "frontEnd" }
  ],
  backEnd: [
    { name: "Taylor", module: "3BE", track: "backEnd" },
    { name: "Brittany", module: "2BE", track: "backEnd" },
    { name: "Robbie", module: "3BE", track: "backEnd" }
  ]
}