javascrptコード多重の継承


参考資料:
「JavaScriptモード」(<)
中国電力出版社です.Styan Stefanov著、陳新訳.
 
 
1.原型継承
var Main = {};

/**
    
prototypal inheitance.
*/
Main.createObj = function(o){
    function F() {};
    F.prototype = o;
    return new F();
};

function Person(pName){
    this.name = pName || "Adam";
};

Person.prototype.getName = function() {
return this.name;
};

Person.prototype.color = "red";

Main.testPrototypal = function(o){
    var papa = new Person();
    var kid = Main.createObj(papa);
    
    console.info(kid.getName());
    console.info("kid-name:" + kid.hasOwnProperty("name"));
    console.info("kid-color:" + kid.hasOwnProperty("color"));
    console.info("kid-getName:" + kid.hasOwnProperty("getName"));
    
    console.info("papa-name:" + papa.hasOwnProperty("name"));// papa-name:true
    console.info("papa-color:" + papa.hasOwnProperty("color"));
    console.info("papa-getName:" + papa.hasOwnProperty("getName"));
};
 
 
2.属性のコピーによる継承が可能です.
2.1レプリカ
/**
        --    (shallow copy)
!! */ Main.extend = function(parent, child) { var i; child = child || {}; for (i in parent) { if (parent.hasOwnProperty(i)) { child[i] = parent[i]; } } return child; }; /** */ Main.testShallowCopy = function(){ console.info(" >>> Main.testShallowCopy"); var Car = { doors: [1,2,3,4], energy: {price: "$2.00"} }; var oneCar = Main.extend(Car); // !! oneCar.doors.push(9); // oneCar.doors, 1,2,3,4,9 console.info("oneCar.doors, " + oneCar.doors.toString()); // Car.doors, 1,2,3,4,9 console.info("Car.doors, " + Car.doors.toString()); };
2.2深さコピー 
 
/**
        --     (deep copy)
*/ Main.extendDeep = function(parent, child) { var i, toStr = Object.prototype.toString, astr = "[object Array]"; child = child || {}; for(i in parent) { if(parent.hasOwnProperty(i)){ if(typeof parent[i] === "object"){ child[i] = (toStr.call(parent[i]) === astr) ? []:{}; Main.extendDeep(parent[i], child[i]); }else{ child[i] = parent[i]; } } } return child; }; /** */ Main.testDeepCopy = function(){ console.info(" >>> Main.testDeepCopy"); var Car = { doors: [5,6,7,8], energy: {price: "$2.00"} }; var oneCar = Main.extendDeep(Car); // !! oneCar.doors.push(1); // oneCar.doors, 5,6,7,8,1 console.info("oneCar.doors, " + oneCar.doors.toString()); // Car.doors, 5,6,7,8 console.info("Car.doors, " + Car.doors.toString()); };