zoo.js

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

function Animal (name, feet)
{
this.name = name;
this.feet = feet;

// this wasn't passing the last test, 
// it look like each new animal creates its own implemantation of the function

// this.identify = function() {
//   return "I am a " + this.name + " with " + this.feet + " legs.";
//   };
};


//this passes the last test. All the animals share the same implementation
Animal.prototype.identify = function() {
  return "I am a " + this.name + " with " + this.feet + " legs.";
};

var Zoo = {
  init: function(aninals) {
  this.animals = animals;
  },

  bipeds: function() {
    ary = new Array();
    for (x = 0; x < this.animals.length; x++){
      console.log(animals[x].name)
      if (animals[x].feet === 2){
        ary.push(animals[x]);
      }  
    }
    return ary;

  },

  quadrupeds: function() {
    ary = new Array();
    for (x = 0; x < this.animals.length; x++){
      console.log(animals[x].name)
      if (animals[x].feet === 4){
        console.log('inside if');
        ary.push(animals[x]);
      }  
    }
    return ary;
  }

};

//------------------------------------------------------------------------------------------------------------------
// 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"
);