class IFactory { public: virtual IUser* CreateUser() = 0; virtual IDepartment *CreateDepartment() = 0; }; class SqlServerFactory: public IFactory { public: IUser* CreateUser() override { return new SqlServerUser(); } IDepartment* CreateDepartment() override { return new SqlServerDepartment...
Object.create(b):((__.prototype=b.prototype),new__());};varAnimal=(function(){functionAnimal(name){this.name=name;}returnAnimal;})();varCat=(function(_super){__extends(Cat,_super);functionCat(){_super.
constx:[string,number]=['hello',0]// 上述元组可以看做为:interfaceTupleextendsArray<string|number>{0:string;1:number;length:2;} object。表示非原始类型。比如枚举、数组、元组都是 object 类型。 枚举类型 声明枚举类型时,如果没有显式的赋值,那么枚举值从 0 递增。如果显式赋值,那么后面的值从当前值...
functionuseRef<T>(initialValue: T|null): RefObject<T>;//convenience overload for potentially undefined initialValue / call with 0 arguments//has a default to stop it from defaulting to {} instead/** * `useRef` returns a mutable ref object whose `.current` property is initialized to the pa...
class MyClass {/*** This event is fired whenever the application navigates to a new page.* @eventProperty*/public readonly navigatedEvent: FrameworkEvent<NavigatedEventArgs>;} 1.2.7@example 指示应作为示例演示如何使用 API 的文档部分。 它可能包括代码示例。
To start using xterm.js on your browser, add thexterm.jsandxterm.cssto the head of your HTML page. Then create a<div id="terminal"></div>onto which xterm can attach itself. Finally, instantiate theTerminalobject and then call theopenfunction with the DOM object of thediv. ...
classX{publicname:string=''}letx: X = {name:'x'};console.log(x.name);lety = ['a','b','c'];console.log(y[2]);// 在需要通过非标识符(即不同类型的key)获取数据的场景中,使用Map< Object, some_type >。letz =newMap<Object,string>(); ...
类(Class):定义了一件事物的抽象特点,包含它的属性和方法 对象(Object):类的实例,通过new生成 面向对象(OOP)的三大特性:封装、继承、多态 封装(Encapsulation):将对数据的操作细节隐藏起来,只暴露对外的接口。外界调用端不需要(也不可能)知道细节,就能通过对外提供的接口来访问该对象,同时也保证了外界无法任意更改...
val && typeof val === "object" && "x" in val && "y" in val && typeof val.x === "number" && typeof val.y === "number"; } } function f(value: unknown) { if (value instanceof Point) { // Can access both of these - correct! value.x; value.y; // Can't access ...
This tells TypeScript that the class is only meant to be extended from, and that certain members need to be filled in by any subclass to actually create an instance. Copy abstract class Shape { abstract getArea(): number; } // Error! Can't instantiate an abstract class. new Shape(); ...