如果您来自基于类的静态类型的面向对象的语言（例如Java，C++或C＃），那么我假设您正在尝试创建与“类型”相关但与实例无关的变量或方法。
使用带有构造函数的“经典”方法的示例可能会帮助您了解基本的OO Javascript概念：
function MyClass () { // constructor function var privateVariable = "foo"; // Private variable this.publicVariable = "bar"; // Public variable this.privilegedMethod = function () { // Public Method alert(privateVariable); };}// Instance method will be available to all instances but only load once in memory MyClass.prototype.publicMethod = function () { alert(this.publicVariable);};// Static variable shared by all instancesMyClass.staticProperty = "baz";var myInstance = new MyClass();staticProperty是在MyClass对象（它是一个函数）中定义的，并且与创建的实例无关，Javascript将函数视为一等对象，因此作为对象，可以为函数分配属性。
更新： ES6引入了通过关键字声明类的功能
class。它是对现有基于原型的继承的语法糖。
该
static关键字允许您轻松地在一个类中定义的静态属性或方法。
让我们看一下上面用ES6类实现的示例：
class MyClass { // class constructor, equivalent to // the function body of a constructor constructor() { const privateVariable = 'private value'; // Private variable at the constructor scope this.publicVariable = 'public value'; // Public property this.privilegedMethod = function() { // Public Method with access to the constructor scope variables console.log(privateVariable); }; } // Prototype methods: publicMethod() { console.log(this.publicVariable); } // Static properties shared by all instances static staticProperty = 'static value'; static staticMethod() { console.log(this.staticProperty); }}// We can add properties to the class prototypeMyClass.prototype.additionalMethod = function() { console.log(this.publicVariable);};var myInstance = new MyClass();myInstance.publicMethod(); // "public value"myInstance.additionalMethod(); // "public value"myInstance.privilegedMethod(); // "private value"MyClass.staticMethod(); // "static value"
