René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"JavaScript设计模式 - learning logs","articleBody":"### 类\n\n``` javascript\n// 一个类\nvar checkObject = function() {\n    this.checkName = function() {};\n    this.checkEmail = function() {};\n    this.checkPassword = function() {};\n};\n\nvar a = new checkObject();\na.checkName();\n```\n\n所有通过`this`定义的方法放在了函数内部，所以每一次通过`new`关键字创建新对象时候，新创建的对象都会对类的`this`上的属性进行复制。所以这些新创建的对象都会有自己的一套方法，造成的消耗很奢侈。\n\n``` javascript\nvar checkObject = function() {};\n\ncheckObject.prototype = {\n    checkName: function() {\n        // 验证姓名\n        return this;\n    },\n    checkEmail: function() {\n        // 验证邮箱\n        return this;\n    },\n    checkPassword: function() {\n        // 验证密码\n        return this;\n    }\n}\n\nvar a = new checkObject();\na.checkName().checkEmail().checkPassword();\n```\n\nthis指向当前对象（a）\n\n\u003e 有一些方法没有返回值，例如，一些设置或修改对象的某个状态却不返回任何值的方法。\n\u003e 让这些方法返回`this`而不是`undefined`（没有`return`默认返回`undefined`），就可以启动级联（Cascade）。\n\u003e 让每一方法都返回该对象，所以每次调用的结果可以被下一次调用所用。\n\u003e 一个接口没必要一次做太多事\n\n```\nvar Book = function (bookId, bookName, price) {\n    var num = 1;  //  私有属性\n    function checkId () {};  //  私有方法\n\n    // 对象共有属性\n    this.bookId = bookId;\n\n    // 对象共有方法\n    this.copy = function () {};\n    // 特权方法\n    this.getName = function() {};\n    this.getPrice = function() {};\n    this.setName = function() {};\n    this.setPrice = function() {};\n\n    // 构造器\n    this.setName(bookName);\n    this.setPrice(price);\n};\n\nvar aBook = new Book(01,'YOU DON`T KNOW JS',49);\n```\n","author":{"url":"https://github.com/K0II","@type":"Person","name":"K0II"},"datePublished":"2016-06-10T11:55:15.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":5},"url":"https://github.com/7/JavaScript/issues/7"}