JavaScript - Extra strength objects: Using Prototypes(instance, property, hasOwnProperty method)

Head First JavaScript Programming
( O'Reilly Media)
Eric T. Freeman (著), Elisabeth Robson (著)

開発環境

• OS X Mavericks - Apple(OS)
• Safari, Firefox + Firebug, Google Chrome(Webプラウザ、プラグイン)
• BBEdit - Bare Bones Software, Inc. (GUI) , Emacs (CUI) (Text Editor)
• JavaScript (プログラミング言語)

Head First JavaScript Programming (Eric T. Freeman (著)、 Elisabeth Robson (著)、 O'Reilly Media )のChapter 13(Extra strength objects: Using Prototypes)、EXERCISE(p.587)を解いてみる。

EXERCISE(p.587)

コード(BBEdit, Emacs)

var Robot = function (name, year, owner) {
        this.name = name;
        this.year = year;
        this.owner = owner;
    },
    robby,
    rosie;

Robot.prototype.maker = 'ObjectsRUs';
Robot.prototype.errorMessage = 'All systems go.';
Robot.prototype.reportError = function () {
    print(this.name + ' says ' + this.errorMessage);
};
Robot.prototype.spillWater = function () {
    this.errorMessage = 'I appear to have a short circuit!';
};

robby = new Robot('Robby', 1956, 'Dr.Morbius');
rosie = new Robot('Rosie', 1962, 'George Jetson');

rosie.reportError(); // All systems go.
robby.reportError(); // All systems go.
robby.spillWater();
rosie.reportError(); // All systems go.
robby.reportError(); // I appear to have a short circuit!

print(robby.hasOwnProperty('errorMessage')); // true
print(rosie.hasOwnProperty('errorMessage')); // false