zoo.js

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

Animal.prototype.identify = function(){
  return "I am a "+this.name+" with "+this.leg_count+" legs."
}

Zoo = {
  animals: animals,
  init: function(animals) {
    this.animals = animals;
  },
  bipeds: function(){
    return animals.filter(function(animal) { return animal.leg_count == 2 })
  },
  quadrupeds: function(){
    return animals.filter(function(animal) { return animal.leg_count == 4 })
  }
}

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

console.log("putting animals here...")
console.log(animals[0].identify())

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"
);