Code Year 2012 - Week 6

今週はprototype。
prototypeプロパティに代入することで、動的にクラス階層を変えられるのがすごい。

	// 1. An Objective Review
	var james = {
	// add properties to this object!
	job: "programmer",
	married: false
	};
	function Person(job, married) {
	this.job = job;
	this.married = married;
	}
	// create a "gabby" object using the Person constructor!
	var gabby = new Person("student", true);
	// 2. Fun with Functions
	function Person(job, married) {
	this.job = job;
	this.married = married;
	// add a "speak" method to Person!
	this.speak = function() {
	console.log("Hello!");
	};
	}
	// 3. Literary Speaking
	var james = {
	job: "programmer",
	married: false,
	speak: function(feel) {
	console.log("Hello, I am feeling " + feel);
	}
	};
	james.speak("great");
	james.speak("just okay");
	// 4. Can I See Your References?
	var james = {
	job: "programmer",
	married: false,
	sayJob: function() {
	// complete this method
	console.log("Hi, I work as a " + this.job);
	}
	};
	// james' first job
	james.sayJob();
	// change james' job to "super programmer" here
	james.job = "super programmer";
	// james' second job
	james.sayJob();
	// 5. Who's in Your Bracket?
	var james = {
	job: "programmer",
	married: false
	};
	// set to the first property name of "james"
	var aProperty = james.job;
	// print the value of the first property of "james"
	// using the variable "aProperty"
	console.log(james['job']);
	console.log(aProperty);

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	// 1. I.D., Please
	// complete these definitions so that they will have
	// the appropriate types
	var anObj = { job: "I'm an object!" };
	var aNumber = 42;
	var aString = "I'm a string!";
	console.log(typeof(anObj)); // should print "object"
	console.log(typeof(aNumber)); // should print "number"
	console.log(typeof(aString)); // should print "string"
	// 2. Know Thyself
	var myObj = {
	// finish myObj
	name: "name"
	};
	console.log( myObj.hasOwnProperty('name') ); // should print true
	console.log( myObj.hasOwnProperty('nickname') ); // should print false
	// 3. Dressed to Impress
	var suitcase = {
	shirt: "Hawaiian"
	};
	if(suitcase.hasOwnProperty('shorts')){
	console.log(suitcase.shorts);
	}else{
	suitcase.shorts = "shorts";
	console.log(suitcase.shorts);
	}
	// 4. Getting IN-timate
	var nyc = {
	fullName: "New York City",
	mayor: "Michael Bloomberg",
	population: 8000000,
	boroughs: 5
	};
	// write your for-in loop here
	for(v in nyc){
	console.log(v);
	}
	// 5. List ALL the Properties!
	var nyc = {
	fullName: "New York City",
	mayor: "Michael Bloomberg",
	population: 8000000,
	boroughs: 5
	};
	// write a for-in loop to print the value of nyc's properties
	for(var property in nyc){
	console.log(nyc[property]);
	}

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	// 1. Class is in Session
	function Person(name,age) {
	this.name = name;
	this.age = age;
	};
	// Let's make bob again, using our constructor
	var bob = new Person("Bob Smith", 30);
	var susan = new Person("Susan Jordan", 35);
	// make your own class here
	function Circle(radius){
	this.radius = radius;
	};
	// 2. Teach Snoopy
	function Dog (breed) {
	this.breed = breed;
	};
	// here we make buddy and teach him how to bark
	var buddy = new Dog("Golden Retriever");
	buddy.bark = function() {
	console.log("Woof");
	};
	buddy.bark();
	// here we make snoopy
	var snoopy = new Dog("Beagle");
	// we need you to teach snoopy how to bark here
	snoopy.bark = function() {
	console.log("Woof");
	}
	// this causes an error, because snoopy doesn't know how to bark!
	snoopy.bark();
	// 3. How do Classes Help Us?
	function Person(name,age) {
	this.name = name;
	this.age = age;
	};
	// a function that prints the name of any given person
	function printPersonName(p) {
	console.log(p.name);
	};
	var bob = new Person("Bob Smith", 30);
	printPersonName(bob);
	// make a person called me with your name and age
	// then use printPersonName to print your name
	var me = new Person("Manabu", 29);
	printPersonName(me);
	// 4. Prototype to the Rescue
	function Dog (breed) {
	this.breed = breed;
	};
	// here we make buddy and teach him how to bark
	var buddy = new Dog("golden Retriever");
	Dog.prototype.bark = function() {
	console.log("Woof");
	};
	buddy.bark();
	// here we make snoopy
	var snoopy = new Dog("Beagle");
	/// this time it works!
	snoopy.bark();
	// 5. Prototype Practice
	function Cat(name, breed) {
	this.name = name;
	this.breed = breed;
	}
	// let's make some cats!
	var cheshire = new Cat("Cheshire Cat", "British Shorthair");
	var gary = new Cat("Gary", "Domestic Shorthair");
	// add a method "meow" to the Cat class that will allow
	// all cats to print "Meow!" to the console
	Cat.prototype.meow = function() {
	console.log("Meow!");
	}
	// add code here to make the cats meow!
	cheshire.meow();
	gary.meow();

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	// 1. It's All in the Genes
	// create your Animal class here
	function Animal(name, numLegs){
	this.name = name;
	this.numLegs =numLegs;
	}
	// create the sayName method for Animal
	Animal.prototype.sayName = function() {
	console.log("Hi my name is " + this.name);
	}
	// provided code to test above constructor and method
	var penguin = new Animal("Captain Cook", 2);
	penguin.sayName();
	// 2. Marching Penguins
	// create your Animal class here
	function Animal(name, numLegs){
	this.name = name;
	this.numLegs =numLegs;
	}
	// create the sayName method for Animal
	Animal.prototype.sayName = function() {
	console.log("Hi my name is " + this.name);
	}
	function Penguin(name, numLegs){
	this.name = name;
	this.numLegs =numLegs;
	}
	Penguin.prototype.sayName = function() {
	console.log("Hi my name is " + this.name);
	}
	// provided code to test above constructor and method
	var penguin = new Penguin("Captain Cook", 2);
	penguin.sayName();
	// 3. DRY Penguins
	// the original Animal class and sayName method
	function Animal(name, numLegs) {
	this.name = name;
	this.numLegs = numLegs;
	}
	Animal.prototype.sayName = function() {
	console.log("Hi my name is "+this.name);
	};
	// define a Penguin class
	function Penguin(name) {
	this.name = name;
	this.numLegs = 2;
	}
	// set its prototype to be a new instance of Animal
	Penguin.prototype = new Animal();
	// 4. Black (and White) Penguin Magic
	// the original Animal class and sayName method
	function Animal(name, numLegs) {
	this.name = name;
	this.numLegs = numLegs;
	}
	Animal.prototype.sayName = function() {
	console.log("Hi my name is "+this.name);
	};
	// define a Penguin class
	function Penguin(name) {
	this.name = name;
	this.numLegs = 2;
	}
	// set its prototype to be a new instance of Animal
	Penguin.prototype = new Animal();
	var penguin = new Penguin("pen-chan");
	penguin.sayName();
	// 5. Penguins, Properties, and the Prototype
	function Penguin(name) {
	this.name = name;
	this.numLegs = 2;
	}
	// create your Emperor class here and make it inherit from Penguin
	function Emperor(name) {
	this.name = name;
	}
	Emperor.prototype = new Penguin();
	// create an "emperor" object and print the number of legs it has
	var emperor = new Emperor("pen-suke");
	console.log(emperor.numLegs);
	// 6. Up the Food-I-mean-Prototype Chain
	// original classes
	function Animal(name, numLegs) {
	this.name = name;
	this.numLegs = numLegs;
	this.isAlive = true;
	}
	function Penguin(name) {
	this.name = name;
	this.numLegs = 2;
	}
	function Emperor(name) {
	this.name = name;
	this.saying = "Waddle waddle";
	}
	// set up the prototype chain
	Penguin.prototype = new Animal();
	Emperor.prototype = new Penguin();
	var myEmperor = new Emperor("Jules");
	console.log( myEmperor.saying ); // should print "Waddle waddle"
	console.log( myEmperor.numLegs ); // should print 2
	console.log( myEmperor.isAlive ); // should print true

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	// 1. Open to the Public
	function Person(first,last,age) {
	this.firstName = first;
	this.lastName = last;
	this.age = age;
	}
	var john = new Person('John','Smith',30);
	var myFirst = john.firstName;
	var myLast = john.lastName;
	//declare variable myAge set to the age of the john object.
	var myAge = john.age;
	// 2. Private Variables
	function Person(first,last,age) {
	this.firstname = first;
	this.lastname = last;
	this.age = age;
	var bankBalance = 7500;
	}
	// create your Person
	var john = new Person("John", "Brown", 18);
	// try to print his bankBalance
	console.log(john.bankBalance);
	// 3. Accessing Private Variables
	function Person(first,last,age) {
	this.firstname = first;
	this.lastname = last;
	this.age = age;
	var bankBalance = 7500;
	this.getBalance = function() {
	// your code should return the bankBalance
	return bankBalance;
	};
	}
	var john = new Person('John','Smith',30);
	console.log(john.bankBalance);
	// create a new variable myBalance that calls getBalance()
	var myBalance = john.getBalance();
	console.log(myBalance);
	// 4. Private Methods
	function Person(first,last,age) {
	this.firstname = first;
	this.lastname = last;
	this.age = age;
	var bankBalance = 7500;
	var returnBalance = function() {
	return bankBalance;
	};
	// create the new function here
	this.askTeller = function() {
	return returnBalance;
	};
	}
	var john = new Person('John','Smith',30);
	console.log(john.returnBalance);
	var myBalanceMethod = john.askTeller();
	var myBalance = myBalanceMethod();
	console.log(myBalance);
	// 5. Passing Arguments
	function Person(first,last,age) {
	this.firstname = first;
	this.lastname = last;
	this.age = age;
	var bankBalance = 7500;
	this.askTeller = function(pass) {
	if (pass == 1234) return bankBalance;
	else return "Wrong password.";
	};
	}
	var john = new Person('John','Smith',30);
	/* the variable myBalance should access askTeller()
	with a password as an argument */
	var myBalance = john.askTeller(1234);

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	// 1. Looks For-In to me
	var languages = {
	english: "Hello!",
	french: "Bonjour!",
	notALanguage: 4,
	spanish: "Hola!"
	};
	// print hello in the 3 different languages
	for(var property in languages){
	if("string" === typeof(languages[property])){
	console.log(languages[property]);
	}
	}
	// 2. Hello? Yes, This is Dog
	function Dog (breed) {
	this.breed = breed;
	};
	// add the sayHello method to the Dog class
	// so all dogs now can say hello
	Dog.prototype.sayHello = function() {
	console.log("Hello this is a " + this.breed + " dog");
	};
	var yourDog = new Dog("golden retriever");
	yourDog.sayHello();
	var myDog = new Dog("dachshund");
	myDog.sayHello();
	// 3. So Meta I Can't Take It!
	// what is this "Object.prototype" anyway...?
	var prototypeType = typeof(Object.prototype);
	console.log(prototypeType);
	// now let's examine it!
	var hasOwn = Object.prototype.hasOwnProperty("hasOwnProperty");
	console.log(hasOwn);
	// 4. Private Eye
	function StudentReport() {
	var grade1 = 4;
	var grade2 = 2;
	var grade3 = 1;
	this.getGPA = function() {
	return (grade1 + grade2 + grade3) / 3;
	};
	}
	var myStudentReport = new StudentReport();
	for(var property in myStudentReport) {
	if(typeof myStudentReport[property] !== "function") {
	console.log("Muahaha! "+myStudentReport[property]);
	}
	}
	console.log("Your overall GPA is "+myStudentReport.getGPA());

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