bob.js

// The first thing I want to do is create a Bob constructor for instantiating
// new Bob objects. I don't need to do any initializing, so this is pretty much
// a empty constructor.

function Bob() {};

// I'm going to store all of the functionality in Bob's prototype. This way,
// all of my Bob instances will share the same set of methods.

// Theoretically, I could use a conditional or a switch statement here, but
// I've chosen to just return out of the function if the condition is met.

Bob.prototype.hey = function (statement) {

  if (isShouting(statement)) return 'Woah, chill out!';

  if (isQuestion(statement)) return 'Sure.';

  if (isSilent(statement)) return 'Fine. Be that way!';

  return 'Whatever.';

};

Bob.prototype.isTeenager = function () { return true; };
Bob.prototype.isAdult = function () { return !this.isTeenager(); };

// I've abstracted all of my conditional checks into methods because it's
// self-documenting. Each function returns a boolean. Unfortunately, I
// can't use a "?" in the method name like you can in Ruby.

function hasLetters(statement) {
  return statement.match(/[A-Za-z]/);
};

function isUpperCase(statement) {
  return statement.toUpperCase() === statement;
};

function isShouting(statement) {
  return hasLetters(statement) && isUpperCase(statement);
};

function isQuestion(statement) {
  return statement.slice(-1) === '?';
};

function isSilent(statement) {
  return !statement.trim();
};

module.exports = Bob;