zoo.js

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

function Animal ( name, num_of_legs ) {
  this.name = name;
  this.num_of_legs = num_of_legs;
}

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

var Zoo = {}


Zoo.init = function(animals) {

  var animals = animals;

}


Zoo.bipeds = function() {

  var bipeds = []

  for ( i = 0; i < animals.length;  i++ ) {
    if ( animals[i]["num_of_legs"] === 2 ) {
      bipeds.push(animals[i])
    };
  };

  return bipeds

}


Zoo.quadrupeds = function() {

  var quadrupeds = []

  for ( i = 0; i < animals.length;  i++ ) {
    if ( animals[i]["num_of_legs"] === 4 ) {
      quadrupeds.push(animals[i])
    };
  };

  return quadrupeds

}

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