programming-intro-1.js

// variables 
// control flow 
// functions

// lamp exercise

var on;

function turnOn() {
  if (!isOn()) {
    on = true;
  }
}

function turnOff() {
  if (isOn()) {
    on = false;
  }
}

function isOn() {
  return on;
}

// what if
// I try to turn on a lamp that's already on?
// Does it change for off?
// We want to model other operations? Could you think of any?

// elevator exercise

var currentFloor,
    capacity,
    people,
    floors;

function goTo(floorNumber) {
  if (floorNumber >= floors) {
    currentFloor = floors;
  } else if (floorNumber <= 0) {
    currentFloor = 0;
  } else {
    currentFloor = floorNumber;
  }
}

function loadPeople(quantity) {
  if (people + quantity >= capacity) { 
    people = capacity;
  } else {
    people = people + quantity;
  }
}

function unloadPeople(quantity) {
  if (quantity >= people) {
    people = 0;
  } else {
    people = people - quantity;
  }
}


// What if
// You try to load more people than the capacity
// You try to unload more people than there are in the elevator?
// You try to go to a floor that does not exist?