TypeScript tutor

静的型付け

var x:number  = 10;
x = "hello";

コンパイルエラーとなります。

var x:number  = 10;
x = "hello";

様々な型

// number, string boolean, any
var i = 10;
var x; // var x: any

var results: number[]
results = [10, 5, 3]

列挙型

enum Signal {
  Red = 0,
  Blue = 1,
  Yellow = 2
}
var result: Signal;

// if (result === Signal.Yellow){}
// if (result === Signal['Yellow']){}
console.log(Signal[2])

関数宣言

function add(a: number, b?: number): number {
 if (b){
 return a + b;
 } else{
 return a + a;
 }
}

console.log(add(5, 3));

関数式

var add = (a: number, b: number): number =>{
 return a + b;
}
var add = (a: number, b: number): number => a + b
console.log(add(5, 3));

関数のオーバーロード

function add(a: number, b: number): number; //シグネチャ
function add(a: string, b: string): string;

function add(a: any, b: any): any {
 if(typeof a === "string" && typeof b === "string"){
 return a + " " + b;
 }
 return  a + b;
}
console.log(add(5, 3));
console.log(add("hello", "world"));

class

class User {
  name: string;
  constructor(name: string){
     this.name = name;
  }
  sayHi(); void {
  console.log("hi! i am " + this.name);
  }
}

var tom = new User("tom");
console.log(tom.name);
tom.sayHi();

getter, setter

class User {
  name: string;
  constructor(private _name: string){
     this.name = name;
  }
  sayHi(); void {
  console.log("hi! i am " + this.name);
  }
  get name(){
   return this._name;
  }
  set name(newValue: string){
    this._name = newValue;
  }
}

extends, override

class User {
  name: string;
  constructor(private _name: string){
     this.name = name;
  }
  sayHi(); void {
  console.log("hi! i am " + this.name);
  }
}

class AdminUser extends User{
 private _age: number;
 constructor(_name: string, _age: number){
  super(_name);
  this._age = _age;
 }
  public sayHi(): void {
    console.log("my age:" + this._age);
    super.sayHi();
  }
}

private:メソッドの中のみ可能
protected:クラスの中のみアクセス可能

静的メンバ:static

class User {
  name: string;
  constructor(private _name: string){
     this.name = name;
     User.count++;
  }
  sayHi(); void {
  console.log("hi! i am " + this.name);
  }
  static count: number = 0;
  
}

インターフェイス

interface Result {
  a: number;
  b: number;
}


function getTotal(result: {a: number; b: number}){
  return result.a + result.b;
}

var result = {
 a: 32,
 b: 58
};

console.log(getTotal(result));

interfaceの継承

interface SpringResult {
  a: number;
}

interface FallResult{
 b: number;
}

interface FinalResult extends SpringResult, FallResult {
 final?: number;
}

ジェネリクス

function getArray<T>(value: T): T[]{
 return[value, value, value];
}

console.log(getArray<number>(3));
console.log(getArray<string>("hello"));

ジェネリクスの制約

interface Result {
  a: number;
  b: number;
}


class MyData<T extends Result>{
  constructor(public value: T){}
  getArray(): T[]{
    return [this.value, this.value, this.value];
  }
}

内部モジュール

module UserModule{
  export var name = "yamada";
  export modlue AddressModlue {
     var zip = "123-4567"
  }
}

console.log(UserModule.name);
console.log(UserModlue.AddressModlue.zip);

Getting started Type Script

TypeScriptは大規模開発にも適したjavascriptの拡張ランゲージです。microsftが開発しています。npmでインストールします。

[vagrant@localhost typescript]$ sudo npm install -g typescript
/usr/bin/tsc -> /usr/lib/node_modules/typescript/bin/tsc
/usr/bin/tsserver -> /usr/lib/node_modules/typescript/bin/tsserver
typescript@2.0.10 /usr/lib/node_modules/typescript

拡張子はtsを使います。
main.ts

class User {

}

console.log("hello world")

変換後のjsファイルです。
main.js

var User = (function () {
    function User() {
    }
    return User;
}());
console.log("hello world");
[vagrant@localhost typescript]$ tsc main.ts
[vagrant@localhost typescript]$ ls
main.js  main.ts
[vagrant@localhost typescript]$ node main.js
hello world