TypeScript 基本语法
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
基本数据类型
Boolean
//Boolean
var isDone:boolean = false;
Number
//Number
var width:number = 100;
String
//String
var name:string = "hello";
Array
//Array
var list:number[] = [1, 2, 3];
var list:Array<number>=[1, 2, 3];
Enum
//Enum
enum Color {Red, Green, Blue}
var c: Color = Color.Red;
alert(c)//默认值从0开始，alert(0);
//可以手动指定值
enum Color1 {Red = 1, Green, Blue}
var c1: Color1 = Color1.Green;
alert(c1);//alert(2)
//根据值查找名称
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);
}
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public
constructor(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 public
get 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)
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;}
可选属性
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");
}
}
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()'
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");
else alert("年龄");
}
student("Tom");//alert("姓名")student(15);//alert("年龄")
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>) { // ...}
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 {
export class Zebra { }
}
module Animals {
export interface Legged {
numberOfLegs: number;
}
export class Dog { }
}
//相当于
module Animals {
export interface Legged { numberOfLegs: number; }
export class Zebra { }
export class 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;
}
}
}
