zoo.js

//------------------------------------------------------------------------------------------------------------------
// YOUR CODE: Create your Zoo "object literal" and Animal "constructor" and "prototypes" here.
//------------------------------------------------------------------------------------------------------------------
var Animal = function (name, legs) {
  this.name = name;
  this.legs = legs;
};

var Zoo = {
  ZooArray: [],
  init: function(animals) {
    for (i = 0; i < animals.length; i++){this.ZooArray.push(animals[i]);}
  },
  bipeds: function () {
    bipedArray = [];
    for (i = 0; i < this.ZooArray.length; i++) {
    
      if (this.ZooArray[i].legs === 2) {
        bipedArray.push(this.ZooArray[i]);
      };
    }
    return bipedArray;
  },
  quadrupeds: function () {
    quadrupedArray = [];
    for (i = 0; i < this.ZooArray.length; i++) {
    
      if (this.ZooArray[i].legs === 4) {
        quadrupedArray.push(this.ZooArray[i]);
      };
    }
    return quadrupedArray;
  }
};


Animal.prototype.identify = function () {
  "I am a " + this.name + "with" + this.legs,
  this.name.toLowerCase() + "s have " + this.legs + " legs";
}



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