Object.create() 是什么？
Object.create(proto [, propertiesObject ]) 是E5中提出的一種新的對(duì)象創(chuàng)建方式，第一個(gè)參數(shù)是要繼承的原型，如果不是一個(gè)子函數(shù)，可以傳一個(gè)null，第二個(gè)參數(shù)是對(duì)象的屬性描述符，這個(gè)參數(shù)是可選的。
例如：
function Car (desc) { this.desc = desc; this.color = "red";} Car.prototype = { getInfo: function() { return 'A ' + this.color + ' ' + this.desc + '.'; }};//instantiate object using the constructor functionvar car = Object.create(Car.prototype);car.color = "blue";alert(car.getInfo()); 結(jié)果為:A blue undefined.
1、propertiesObject 參數(shù)的詳細(xì)解釋?zhuān)海J(rèn)都為false）
數(shù)據(jù)屬性：
- writable:是否可任意寫(xiě)
- configurable：是否能夠刪除，是否能夠被修改
- enumerable：是否能用 for in 枚舉
- value：值
訪(fǎng)問(wèn)屬性：
- get(): 訪(fǎng)問(wèn)
- set(): 設(shè)置
2、例子：直接看例子就知道怎么用。
<!DOCTYPE html><html><head> <title>yupeng's document </title> <meta charset="utf-8"/></head><body> <script type="text/javascript"> var obj = { a:function(){ console.log(100) }, b:function(){ console.log(200) }, c:function(){ console.log(300) } } var newObj = {}; newObj = Object.create(obj,{ t1:{ value:'yupeng', writable:true }, bar: { configurable: false, get: function() { return bar; }, set: function(value) { bar=value } } }) console.log(newObj.a()); console.log(newObj.t1); newObj.t1='yupeng1' console.log(newObj.t1); newObj.bar=201; console.log(newObj.bar) function Parent() { } var parent = new Parent(); var child = Object.create(parent, { dataDescriptor: { value: "This property uses this string as its value.", writable: true, enumerable: true }, accessorDescriptor: { get: function () { return "I am returning: " + accessorDescriptor; }, set: function (val) { accessorDescriptor = val; }, configurable: true } }); child.accessorDescriptor = 'YUPENG'; console.log(child.accessorDescriptor); var Car2 = function(){ this.name = 'aaaaaa' } //this is an empty object, like {} Car2.prototype = { getInfo: function() { return 'A ' + this.color + ' ' + this.desc + '.'; } }; var newCar = new Car2(); var car2 = Object.create(newCar, { //value properties color: { writable: true, configurable:true, value: 'red' }, //concrete desc value rawDesc: { writable: true, configurable:true, value: 'Porsche boxter' }, // data properties (assigned using getters and setters) desc: { configurable:true, get: function () { return this.rawDesc.toUpperCase(); }, set: function (value) { this.rawDesc = value.toLowerCase(); } } }); car2.color = 'blue'; console.log(car2.getInfo()); car2.desc = "XXXXXXXX"; console.log(car2.getInfo()); console.log(car2.name); </script></body></html> 結(jié)果為：
100
yupeng
yupeng1
201
I am returning: YUPENG
A blue PORSCHE BOXTER.
A blue XXXXXXXX.
aaaaaa
以上就是針對(duì)javascript一種新的對(duì)象創(chuàng)建方式Object.create()的詳細(xì)介紹，希望對(duì)大家的學(xué)習(xí)有所幫助。
