zoo.js

//------------------------------------------------------------------------------------------------------------------
// YOUR CODE: Create your Zoo "object literal" and Animal "constructor" and "prototypes" here.
//------------------------------------------------------------------------------------------------------------------
 Zoo = {
     
     bipeds: function(){
        return ["human", "monkey", "kangaroo"];
  
     },
     quadrupeds :function(){
        return ["horse", "Cow"];
     },

     init: function(animals){
         return animals
     }
}
 
 function Animal(name, num_legs){
     this.name = name;
     this.num_legs=num_legs;
 }
 
 Animal.prototype.identify = function(){
    return "I am a " + this.name + " with "+this.num_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 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"
);