如何在全局范围内使用ES6模块而不是命名空间？

Question

在ES6中定义类时,它在全局范围内可用,您可以使用新的ES6支架机箱来防止它:

{
  class Car {
    constructor(make) { 
        this.make = make;
        this.currentSpeed = 25;
    }

    getSpeed(){
          console.log(this.make + ' is going ' + this.currentSpeed + ' mph.');
    }
  }
  window.MYNAMESPACE.Car = Car;
}

我有多个js文件,每个文件都有自己的类定义,我在全球范围内通过MYNAMESPACE使这些类可用.因此,从任何地方创建一辆新车看起来像:

var myCar = new MYNAMESPACE.Car();

我怎么能用ES6模块呢？这是可能的,还是值得推荐的？

Answer 1

您应该使用ES6导出和导入,而不是使类在全局范围内可用.

// car.js
class Car {
  constructor(make) { 
        this.make = make;
        this.currentSpeed = 25;
  }

  getSpeed(){
    console.log(this.make + ' is going ' + this.currentSpeed + ' mph.');
  }
}

export default Car;

// foo.js    
import Car from "./car"

var car = new Car("ford");
car.getSpeed();

阅读es6模块语法

1. http://www.2ality.com/2014/09/es6-modules-final.html
2. MDN:
   • https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/class
   • https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/import
   • https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/export