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Object.getPrototypeOf(object):调用对象父类原型上的方法;
function Person(){ this.method1 = function(){alert(1)} } Person.prototype.method2 = function(){alert(2);} function Man(){ this.m1 = function(){ Object.getPrototypeOf(this).method1(); } } Man.prototype = new Person(); Man.prototype.m2 = function(){ Object.getPrototypeOf(this).method2(); } var man = new Man(); man.m1(); man.m2();
Object.getOwnPropertyDescriptor(object, propertyname):获取对象中属性的ECMAScript对象;
var obj = {}; obj.a = "abc"; var descriptor = Object.getOwnPropertyDescriptor(obj, "a"); for(var prop in descriptor){ document.write(prop + ‘: ‘ + descriptor[prop]); document.write("<br />"); } /* configurable: true enumerable: true value: abc writable: true */
Object.defineProperty(object, propertyname, descriptor):将ECMAScript对象设置为对象中的属性.
var obj = {}; obj.a = "abc"; var descriptor = Object.getOwnPropertyDescriptor(obj, "a"); descriptor.writable = false; Object.defineProperty(obj, "a", descriptor); for(var prop in descriptor){ document.write(prop + ‘: ‘ + descriptor[prop]); document.write("<br />"); } /* configurable: true enumerable: true value: abc writable: false */
object.defineProperties(object, descriptors):用 ECMAScript对象 设置为object中多个属性的值.
var obj = {}; obj.a = "abc"; Object.defineProperties(obj,{ a:{ configurable: true, enumerable: true, value: ‘aaa‘, writable: false } }); var descriptor = Object.getOwnPropertyDescriptor(obj, "a"); for(var prop in descriptor){ document.write(prop + ‘: ‘ + descriptor[prop]); document.write("<br />"); } /* configurable: true enumerable: true value: aaa writable: false */
Object.getOwnPropertyNames(object):返回一个由对象属性名组成的数组(包含不可枚举的)
function a(){ this.a=‘1‘; } a.prototype.b=‘2‘; var c=new a(); c.c=‘3‘; alert(Object.getOwnPropertyNames(c));//a,c
Object.create(prototype, descriptors):建立一个原型为[prototype](必需,可为NULL),[descriptors](可选)为ECMAScript对象的对象.
var a = Object.create({a:1,b:2}, { c: { value: "large", enumerable: true }, d: { value: "round", enumerable: true } });
Object.seal(object):锁定对象,无法修改对象的属性,无法加入新的属性.并把ECMAScript对象的configurable设置为false;
var obj = {}; obj.a = "abc"; Object.seal(obj); var descriptor = Object.getOwnPropertyDescriptor(obj, "a"); for(var prop in descriptor){ document.write(prop + ‘: ‘ + descriptor[prop]); document.write("<br />"); } /* configurable: false enumerable: true value: abc writable: true */
Object.freeze(object):冻结对象,无法修改对象的属性,无法加入新的属性.
(与seal的区别为,freeze会把对象的数据属性的Writable设置为false)
var obj = {}; obj.a = "abc"; Object.freeze(obj); var descriptor = Object.getOwnPropertyDescriptor(obj, "a"); for(var prop in descriptor){ document.write(prop + ‘: ‘ + descriptor[prop]); document.write("<br />"); } /* configurable: false enumerable: true value: abc writable: false */
Object.preventExtensions(object):避免加新属性加入对象(Extensible设置为false);
var obj = { a: "1"}; Object.preventExtensions(obj); document.write(Object.isExtensible(obj));//false obj.newProp = 50; document.write(obj.newProp);//undefined
Object.isSealed(object);
Object.isFrozen(object);
Object.isExtensible(object);
判断对象是否为锁定,冻结,不可扩展的.(如果一个对象是冻结的,那其肯定是密封的);
var obj = { a: "1"}; //Object.seal(obj); Object.freeze(obj); //Object.preventExtensions(obj); alert(Object.isSealed(obj)); //alert(Object.isFrozen(obj)); //alert(Object.isExtensible(obj));
Object.keys(object):返回一个由对象可枚举的属性组成的数组.
function a(){ this.a=‘1‘; } var b=new a(); alert(Object.keys(b));//a
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原文地址：http://www.cnblogs.com/makan/p/4725239.html
