quiz.txt

// Name: Charles Tirrell

//////////////////////////////////////////////////////////////// Question 1

const labs = [
  {location: 'Bewkes 107', seats: 15},
  {location: 'Bewkes 109', seats: 25},
  {location: 'Bewkes 144', seats: 7}
];

// A. Generate a new array containing the seat numbers of all the labs (by invoking the built-in map method).

const seats = labs.map(x => x.seats);

//Same as:
//const seats = lab.map(function(x) {
//  return x.seats;
//});

// B. Generate a new array containing only the labs with more than 10 seats (by invoking the built-in filter method).

const bigLabs = labs.filter(x => (x.seats > 10));

// C. Sort the existing array in order of (increasing) seat numbers (by invoking the built-in sort method).

labs.sort((a,b) => a.seats - b.seats);
//////////////////////////////////////////////////////////////// Question 2

const numbers = [5, 4, 3, 2, 1];

// A. Get the first even number (by invoking the built-in find method).

//find gets the first element in the array that satisfies the condition
const found = numbers.find(function(element){
  return element % 2 === 0;
});
console.log(found);

// B. Define a standalone find function. The array is its first argument and the callback is its second argument.
const find = function(array, callback){
  for (const element of array){
    if (callback(element)){
      return element;
    }
  }
}


console.log(find(numbers, function(element){
  for (const element of numbers){
    if (element % 2 === 0){
      return element;
    }
  }
}));

//////////////////////////////////////////////////////////////// Question 3

// This creates the user object described on the quiz.
// It has a question method you can call in part A.
const readline = require('readline');
const user = readline.createInterface({
  input: process.stdin,
  output: process.stdout
});

// A. Make small talk, using traditional callbacks.
user.question("What is your name?", function(response){
  console.log("Hello " + response + ".");

  user.question("How are you doing?", function(response){
    console.log("I am also " + response + ".")
  });
});

// The user.question method doesn't actually return a promise, so here is a question function that does.
// Call this question function in part B instead of calling the user.question method.
const question = function(prompt) {
  return new Promise(resolve => user.question(prompt, resolve));
};


// B. Make small talk again, using promises.
user.question("What is your name?")
  .then(function(resolve){
    console.log("Hello" + resolve + ".");
    return user.question("How are you doing?");
  })
  .then(resolve => console.log("I am also" + resolve + "."))
  .catch(error => console.log(error.stack));
//////////////////////////////////////////////////////////////// Question 4
// Question 4 is commented out because otherwise it would interfere with Question 3.
// When you're ready to work on Question 4, uncomment it and comment out Question 3.

// This function returns a promise, which produces 42 after an asynchronous delay of one second.
const f1 = function() {
  return new Promise(resolve => setTimeout(() => resolve(42), 1000));
};

// This function returns a promise, which produces 24 after an asynchronous delay of one second.
const f2 = function() {
  return new Promise(resolve => setTimeout(() => resolve(24), 1000));
};

// Run f1 and f2 in parallel and log 'f1', 'f2', or 'equal' to indicate which function returned the larger result.

const funcs = {f1, f2};

Promise.all(funcs)
  .then(funcs.sort(a,b) => (a - b))
  .then(console.log(funcs[0]))
  .catch(error => console.log(error.stack));