TypeScript 是微软开发的 JavaScript 的超集,TypeScript兼容JavaScript,可以载入JavaScript代码然后运行。TypeScript与JavaScript相比进步的地方 包括:加入注释,让编译器理解所支持的对象和函数,编译器会移除注释,不会增加开销;增加一个完整的类结构,使之更新是传统的面向对象语言。
TypeScript 微软官方网站 http://www.typescriptlang.org/
TypeScript 源码 http://typescript.codeplex.com我用 TypeScript 语言的七个月 http://www.linuxidc.com/Linux/2013-07/87506.htm
1.基本数据类型
Boolean
//Booleanvar isDone:boolean = false;Number
//Numbervar width:number = 100;String
//Stringvar name:string = "hello";Array
//Arrayvar list:number[] = [1, 2, 3];var list:Array<number>=[1, 2, 3];Enum
//Enumenum Color {Red, Green, Blue}var c: Color = Color.Red;alert(c);//默认下标从0开始,alert(0);//可以手动指定下标enum Color1 {Red = 1, Green, Blue}var c1: Color1 = Color1.Green;alert(c1);//alert(2)//根据下标查找名称enum Color2 {Red = 1, Green=2, Blue=4}var c2: string = Color2[4];alert(c2);//alert(Blue)Any
//不确定类型,退出编译检查var notSure: any = 4;notSure = "maybe a string instead";notSure = false; // okay, definitely a boolean//不确定数组元素类型var anylist:any[] = [1, true, "free"];anylist[1] = 100;Void
//空白function warnUser(): void {alert(123);}2.类
基本语法
class Animal {animalName:string;constructor(name:string) {this.animalName = name;}sayHello() {alert(this.animalName + ": Hello");}}var tom = new Animal("Tom");tom.sayHello();//alert(Tom:Hello)继承
class Animal {animalName:string;constructor(name:string) {this.animalName = name;}sayHello() {alert(this.animalName + ": Hello");}}class Cat extends Animal {//重写sayHello方法sayHello() {alert(this.animalName + "(Cat):" + "Hello");}}class Mouse extends Animal {sayHello() {alert(this.animalName + "(Mouse):" + "Hello");}}var tom:Animal = new Cat("Tom");tom.sayHello();//alert(Tom(Cat):Hello)var jerry:Animal = new Mouse("Jerry");jerry.sayHello();//alert(Jerry(Mouse):Hello)修饰符
当我们把animalName 改为private
class Animal {private animalName:string;//默认是publicconstructor(name:string) {this.animalName = name;}//...}class Cat extends Animal {//重写sayHello方法sayHello() {alert(this.animalName + "(Cat):" + "Hello");//Error 编译不通过}}get,set 访问器
class Animal {private _animalName:string;//默认是publicget animalName():string {return this._animalName;}set animalName(name:string):string {this._animalName = name;}//...}静态属性
//静态属性class Table {static width = 100;static height = 200;}var width = Table.width;alert(width);//alert(100)3.接口
基本语法
interface ICar {color:string;}class Bus implements ICar {color:string;constructor() {this.color = "Blue";}}var bus = new Bus();alert(bus.color);继承接口
//继承接口interface Shape {color: string;}interface PenStroke {penWidth: number;}interface Square extends Shape, PenStroke {sideLength: number;}可选属??
interface ICar {color:string;safetyDevice?:any;//实现类无需实现}function MoveCar(car:ICar){if(car.safetyDevice){alert("The car is safe");}else{alert("The car is not safe");}}4.模块(Modules)
作用:1.防止命名空间冲突;2.将一个功能模块很容易的划分到不同文件中,更容易维护;
基本语法
module MyDemo {export interface IDemo {}export class Demo implements IDemo {}}别名
module Shapes {export module Polygons {export class Triangle { }export class Square { }}}import polygons = Shapes.Polygons;var sq = new polygons.Square(); // 类似于 "new Shapes.Polygons.Square()"5.函数(Function)
基本语法
function add(x:number, y:number):number {return x + y;}// orvar myAdd = function (x:number, y:number):number {return x + y;};完整的函数类型
var myAdd:(x:number, y:number)=>number =function (x:number, y:number):number {return x + y;};为了增强可读性,给参数x、y具有实际的意义,可以这样写
var myAdd:(baseValue:number, increment:number)=>number =function (x:number, y:number):number {return x + y;};第二部分number 是一个返回类型,如果无需返回类型,请使用 "void"
第三部分的function 参数类型,根据上下文类型进行推断,可以省略
var myAdd:(baseValue:number, increment:number)=>number =function (x, y) {return x + y;};可选参数
//可选参数function buildName(firstName:string, lastName?:string) {if (lastName)return firstName + " " + lastName;else return firstName;}var result1 = buildName("Bob");默认参数
//默认参数function buildNameDefaultValue(firstName: string, lastName = "Smith") {return firstName + " " + lastName;}var result1 = buildNameDefaultValue("Bob");可变参数
例如在C#中,方法参数定义使用param int[],调用方法时,就可以传递多个int类型的参数
在TypeScript中
function buildNameRest(firstName:string, ...restOfName:string[]) {return firstName + " " + restOfName.join(" ");}var employeeName = buildNameRest("Joseph", "Samuel", "Lucas", "MacKinzie")Lambads 和this关键字
var people={name:["张三","李四","王五","赵六"],getName:function(){return function(){var i=Math.floor(Math.random()*4);return {n:this.name[i]}}}}var pname=people.getName();alert("名字:"+pname().n);调用发现getName中的this关键字指向的是getName,访问不到外部的name属性
所以我们修改为:
var people = {name: ["张三", "李四", "王五", "赵六"],getName: function () {return()=> {var i = Math.floor(Math.random() * 4);return {n: this.name[i]}}}}var pname = people.getName();alert("名字:" + pname().n);重载
//重载function student(name:string):string;function student(age:number):number;function student(numberorage:any):any {if (numberorage && typeof (numberorage) == "string")alert("姓名");elsealert("年龄");}student("Tom");//alert("姓名")student(15);//alert("年龄")5.泛型
基本语法
function identity<T>(arg: T): T {return arg;}//数组泛型function identity<T>(arg: T[]): T[] {console.log(arg.length);}泛型类型(通用的函数类型)
function identity<T>(arg:T):T {return arg;}var myIdentity:<T>(arg:T)=>T = identity;//T也可使用其他字母表示//也可以这么写//var myIdentity:{<T>(arg:T): T} = identity;接口泛型
interface GenericIdentityFn {<T>(arg:T): T;}function identity<T>(arg:T):T {return arg;}var myIdentity:GenericIdentityFn = identity;泛型类
class GenericNumber<T> {zeroValue:T;add:(x:T, y:T) => T;}var myGenericNumber = new GenericNumber<number>();myGenericNumber.zeroValue = 0;myGenericNumber.add = function (x, y) {return x + y;};泛型约束
interface Lengthwise {length: number;}function loggingIdentity<T extends Lengthwise>(arg:T):T {console.log(arg.length);return arg;}loggingIdentity(3);//errorloggingIdentity({length: 10, value: 3});//只要类型包含length属性即可泛型类约束
class Findable<T>{//...}function find<T>(n: T, s: Findable<T>) {// ...}6.合并
合并接口
interface Box {height: number;width: number;}interface Box {scale: number;}var box: Box = {height: 5, width: 6, scale: 10};合并模块
module Animals {exportclass Zebra { }}module Animals {exportinterface Legged { numberOfLegs: number; }exportclass Dog { }}//相当于module Animals {exportinterface Legged { numberOfLegs: number; }exportclass Zebra { }exportclass Dog { }}合并模块和类
class Album {label:Album.AlbumLabel;}module Album {export class AlbumLabel {}}合并模块和函数
function buildLabel(name:string):string {return buildLabel.prefix + name + buildLabel.suffix;}module buildLabel {export var suffix = "";export var prefix = "Hello, ";}alert(buildLabel("Sam Smith"));合并模块与枚举
enum Color {red = 1,green = 2,blue = 4}module Color {export function mixColor(colorName:string) {if (colorName == "yellow") {return Color.red + Color.green;}else if (colorName == "white") {return Color.red + Color.green + Color.blue;}else if (colorName == "magenta") {return Color.red + Color.blue;}else if (colorName == "cyan") {return Color.green + Color.blue;}}}不能合并
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