编辑代码

function User(name, role) {
  this.name = name;
  this.isAdmin = role ? role : false
  this.sayHi = function(msg) {
      console.log("My name is:", this.name, ",", msg ? msg : "")
  }
}

let user = new User("Jack")
console.log("User Constructor: ", user)
user.sayHi("I am from US.")