text: /**
   * 通过export导出的值是一样的，不同的脚本加载得到结果一样
   */
  export var foo = 'bar';
  setTimeout(() => foo = 'baz', 500);
  
  export let obj = {};
  
  function C() {
    this.sum = 0;
    this.add = function() {
      this.sum += 1;
    }
    this.show = function() {
      console.log(this.sum);
    }
  }
  
  export let c = new C();
  