javascript Object.create() 原意

if (typeof Object.create !== "function") {
    Object.create = function (proto, propertiesObject) {
        if (!(proto === null || typeof proto === "object" || typeof proto === "function")) {
            throw TypeError('Argument must be an object, or null');
        }
        var temp = new Object();
        temp.__proto__ = proto;
        if(typeof propertiesObject === "object")
            Object.defineProperties(temp, propertiesObject);
        return temp;
    };
}

-----------------------------------------------------------------

o = {};
// 等同於:
o = Object.create(Object.prototype);


// Example where we create an object with a couple of sample properties.
// (Note that the second parameter maps keys to *property descriptors*.)
o = Object.create(Object.prototype, {
  // foo 為數值屬性
  foo: { writable: true, configurable: true, value: 'hello' },
  // bar 為 getter-and-setter 訪問屬性
  bar: {
    configurable: false,
    get: function() { return 10; },
    set: function(value) { console.log('Setting `o.bar` to', value); }
/* with ES5 Accessors our code can look like this
    get function() { return 10; },
    set function(value) { console.log('setting `o.bar` to', value); } */
  }
});


function Constructor() {}
o = new Constructor();
// 等同於:
o = Object.create(Constructor.prototype);
// Of course, if there is actual initialization code in the
// Constructor function, the Object.create() cannot reflect it


// 創建一個新物件，指定原型是全新的空物件，並加入值為 42 的屬性'p'
o = Object.create({}, { p: { value: 42 } });