kata15OrganizingInstructorsNEW.js

const organizeInstructors = function(instructors) {
  let output = {};
  for (const index in instructors) {
    if (!output[(instructors[index].course)]) output[instructors[index].course] = [instructors[index].name];
    else {
      output[instructors[index].course].push(instructors[index].name);
    }
  }
  return output;
};

console.log(organizeInstructors([
  {name: "Samuel", course: "iOS"},
  {name: "Victoria", course: "Web"},
  {name: "Karim", course: "Web"},
  {name: "Donald", course: "Web"}
]));

console.log(organizeInstructors([
  {name: "Brendan", course: "Blockchain"},
  {name: "David", course: "Web"},
  {name: "Martha", course: "iOS"},
  {name: "Carlos", course: "Web"}
]));

/*
{
  iOS: ["Samuel"],
  Web: ["Victoria", "Karim", "Donald"]
}
{
  Blockchain: ["Brendan"],
  Web: ["David", "Carlos"],
  iOS: ["Martha"]
}
*/