console 命令行工具 X clear

console

function Foo(name){
  this.name = name;
}

function _new(fn,...args){
  const obj = Object.create(fn.prototype)
  const res = fn.apply(obj,args)
  return res instanceof Object ? res : obj
}

const a = new Foo('张三')
const b = _new(Foo, '李四')
console.log(JSON.stringify(a))
console.log(JSON.stringify(b))

new 函数实现