如何从 Javascript 中的 function 运行 object 方法？

Question

I have a specific task: to create an object (instance of a sub-class) within a function, call a method on that object and then return it. These are the classes:

// Task 1: Code a Person class
class Person {
    constructor(name = "Tom", age = 20, energy = 100) {
        this.name = name;
        this.age = age;
        this.energy = energy;
    }
    sleep() {
        this.energy += 10;
        console.log("Energy has increased, now it's ", this.energy);
    }
    doSomethinFun() {
        this.energy -= 10
        console.log("Energy has decreased, now it's ", this.energy);
    }
}

// Task 2: Code a Worker class
class Worker extends Person {
    constructor(name, age, energy, xp = 0, hourlyWage = 10) {
        super(name, age, energy);
        this.xp = xp;
        this.hourlyWage = hourlyWage;
    }
    goToWork() {
        this.xp += 10
        console.log("XP is nov increased, now it's ", this.xp);
    }
}

I've tested all methods on a custom object instantiated from Worker - they all work. Now the problem(s):

1. The task: Inside the intern function instantiate the Worker class to code a new intern object. The intern should have the following characteristics:

   • name: Bob
   • age: 21
   • energy: 110
   • xp: 0
   • hourlyWage: 10

   As I come to find out they cannot have the same name, so I figured to name the object intern1 because function name was predefined by the task.

    function intern() { var intern1 = new Worker("Bob", 21, 110, 0, 10); console.log(intern1); }

2. The task: Run the goToWork() method on the intern object. Then return the intern object.

    intern1.goToWork(); return intern();

   I guessed the return is on the function which will automatically invoke the object, and so it works. However intern1.goToWork() doesn't. The console throws ReferenceError: intern1 is not defined... as I found out the problem is of scope... but I cannot find the solution. How to execute goToWork() method on intern1?

Answer 1

the function intern() doesnt return anything and yet you returned nothing. If i understood correnctly, you can do something like that:

function intern() {
    return new Worker("Bob", 21, 110, 0, 10);
}
let intern1 = intern();
intern1.goToWork();

Answer 2

This works

function intern() {
  var intern1 = new Worker("Bob", 21, 110, 0, 10);
  intern1.goToWork();
  return intern1;
  }

  const i = intern();
  console.log(i);