zoo.js

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

function Animal(nameOfAnimal, legs){
  var animal = [];
  this.nameOfAnimal = nameOfAnimal;
  this.legs = legs;
}

Zoo = { bipeds :[],
  quadrupeds : [],
  init: function(desiredArray){

    for (i=0; i<=desiredArray.size; i++){
      if(desiredArray[i].legs === 2){
        Zoo.bipeds.push(desiredArray[i]);
      }
      else if (desiredArray[i].legs === 4){
        Zoo.quadrupeds.push(desiredArray[i]);
      }
    }
    function bipeds(){
      bipeds
    }
  }
};

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