zoo.js

//------------------------------------------------------------------------------------------------------------------
// YOUR CODE: Create your Zoo "object literal" and Animal "constructor" and "prototypes" here.
//------------------------------------------------------------------------------------------------------------------

var Zoo = {
  bipeds: [],
  quadrupeds: [],
  other: [],

  init: function(animals){
    this.animals = animals;

    for (var i = 0; i < animals.length; i++){
      if (animals[i].legs == 2){
        this.bipeds.push(animals[i]);
      }
      if (animals[i].legs == 4){
        this.quadrupeds.push(animals[i]);
      }
      else{
        other.push(animals[i]);
      }
    }
  }
};

function Animal(animal, legs) {
  this.animal = animal;
  this.legs = legs;
}

Animal.prototype = {
  identify: function() {
    var what_animal = "I am a " + this.animal + " with " + this.legs + " legs.";
    return what_animal;
  }
};


//------------------------------------------------------------------------------------------------------------------
// DRIVER CODE: Do **NOT** change anything below this point. Your task is to implement code above to make this work.
//------------------------------------------------------------------------------------------------------------------

function assert(test, message) {
  if (!test) {
    throw "ERROR: " + message;
  }
  return true;
}

var animals = [
new Animal("Human", 2),
new Animal("Monkey", 2),
new Animal("Kangaroo", 2),
new Animal("Horse", 4),
new Animal("Cow", 4),
new Animal("Centipede", 100)
];

Zoo.init(animals);

assert(
  Zoo.bipeds().length === 3, "the Zoo should have 3 bipeds"
  );
assert(
  Zoo.quadrupeds().length === 2, "the Zoo should have 2 bipeds"
  );
assert(
  animals[0].identify() === "I am a Human with 2 legs.", "humans have 2 legs"
  );
assert(
  animals[2].name === "Kangaroo", "expected 'Kangaroo'"
  );
assert(
  animals[0].identify === animals[5].identify, "only one implementation of the identify() function should exist"
  );