Collections?

collections.js

var Animal = function(classification, legs_count, size) {
  this.classification = classification;
  this.legs_count = legs_count;
  this.size = size;

}

// An instance method;
Animal.prototype.description = function(){
  return this.size + " " + this.classification + "with " + this.legs_count + " legs";
}

// Namespaced functions
Animal.isDog = function(animal){
  return animal.classification==='dog';
};

Animal.hasOneLeg = function(animal){
  return animal.legs_count===1;
};

//Static Methods
Animal.dogsOnly = function(){
  return Animal.all().filter(Animal.isDog);
}

Animal.oneLeg = function(){
  return Animal.all().filter(Animal.hasOneLeg);
}

Animal.all = function(){
  return [
    new Animal("dog", 4, 'small'),
    new Animal("dog", 1, 'small'),
    new Animal("cat", 4, 'tiny'),
    new Animal("bird", 2, 'iddybiddy'),
    new Animal("cow", 1, 'huge')
  ]
}

// console.log("All the animals");
// console.log(Animal.all());

// console.log("All the dogs");
// console.log(Animal.dogsOnly());

// console.log("Dogs descriptions");
// dogs = Animal.dogsOnly();
// dogs.forEach(function(dog){
//   console.log(dog.description());
// })

// console.log("One legged animals");
// console.log(Animal.oneLeg());


console.log("has one leg")
console.log(Animal.all().filter(Animal.hasOneLeg));

console.log("is a dog")
console.log(Animal.all().filter(Animal.isDog));

console.log("one legged dog, chaining filters")
console.log(Animal.all().filter(Animal.isDog).filter(Animal.hasOneLeg));


//Collections and chaining
console.log("Dogs with one leg");
console.log(Animal.dogsOnly().filter(Animal.hasOneLeg));

//OR
console.log("Dogs with one leg");
console.log(Animal.all().filter(Animal.isDog));//.filter(Animal.hasOneLeg));

//Static
console.log("static")
console.log(Animal.oneLeg());
console.log(Animal.dogsOnly());