模块

// user.ts
export interface User {
  name: string;
  age: number;
}

export function createUser(name: string, age: number): User {
  return { name, age };
}

export class UserManager {
  users: User[] = [];
}

interface User {
  name: string;
  age: number;
}

function createUser(name: string, age: number): User {
  return { name, age };
}

export { User, createUser };

function createUser(name: string, age: number) {
  return { name, age };
}

export { createUser as create };

// user.ts
export default class User {
  name: string;
  age: number;
}

// 或
class User {
  name: string;
  age: number;
}

export default User;

import { User, createUser } from './user';

let user: User = createUser('John', 25);

import { User as UserType } from './user';

let user: UserType = { name: 'John', age: 25 };

import * as UserModule from './user';

let user: UserModule.User = UserModule.createUser('John', 25);

import User from './user';

let user = new User();

import User, { createUser } from './user';

// models/index.ts
export { User } from './user';
export { Product } from './product';
export { Order } from './order';

// 使用
import { User, Product, Order } from './models';

export { User as UserModel } from './user';

export * from './user';
export * from './product';

async function loadUser() {
  const userModule = await import('./user');
  const user = userModule.createUser('John', 25);
  return user;
}

// 或
import('./user').then(module => {
  const user = module.createUser('John', 25);
});

namespace Validation {
  export interface StringValidator {
    isValid(s: string): boolean;
  }

  export class EmailValidator implements StringValidator {
    isValid(s: string): boolean {
      return /\S+@\S+\.\S+/.test(s);
    }
  }
}

let validator = new Validation.EmailValidator();

import { User } from './user';
import { Product } from '../models/product';

import * as React from 'react';
import { Component } from '@angular/core';

// types.d.ts
declare module 'my-library' {
  export function doSomething(): void;
}

// 使用
import { doSomething } from 'my-library';

// global.d.ts
declare global {
  interface Window {
    myCustomProperty: string;
  }
}

export {};

// 扩展已有模块
import { Observable } from 'rxjs';

declare module 'rxjs' {
  interface Observable<T> {
    myCustomMethod(): Observable<T>;
  }
}