Js 函数实现a(),a.a()的定义方法，你还有那种更时尚的写法

Question

const fun = (function(){
  let slef = ()=>console.log(1);
  slef.planB = ()=>console.log(2);
  return slef;
})();

fun();
// 1
fun.planB();
// 2

Answer 1

var fun = new function () { console.log(1); }