FAQ: Classes - Inheritance II

This community-built FAQ covers the “Inheritance II” exercise from the lesson “Classes”.

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This exercise can be found in the following Codecademy content:

Web Development

Introduction To JavaScript

FAQs on the exercise Inheritance II

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Don’t understand how " The Doctor and Nurse classes" become the class HospitalEmployee

3 Likes
class HospitalEmployee {
    //
}

class Doctor extends HospitalEmployee {
    //
}

class Nurse extends HospitalEmployee {
    //
}
4 Likes

thanks,
later I understood it.
Thanks again

1 Like

what is the “extends” thing used for?

Since it inherits from a parent class, it would then be said to extend that class by adding to or overriding parent attributes and methods.

2 Likes

What am I supposed to do with this?

_insurance

1 Like

A post was split to a new topic: Why does the method takeVacationDays change its value?

I don’t really understand what this mean in the instruction 1:

" _remainingVacationDays (set to 20 inside the constructor() ), _insurance"

I basically just simple code in this way, and it failed

class Doctor{

this._name=name;

this._remainingVacationDays=20;

}

class Nurse{

this._name=name;

this._remainingVacationDays=20;

}

A class needs a constructor method.

class Doctor {
    constructor (name) {
        this._name = name;
        this._remainingVacationDays = 20;
    }
}
1 Like

thank you~~~
I will check …

Thanks god, You are here to support us.
It means a lot.

1 Like

class Doctor {
^^^^^^
SyntaxError: Unexpected identifier

class HospitalEmployee {
  constructor (name) {
    this.Doctor, this.Nurse
}
class Doctor {
    constructor (name) {
        this._name = name;
        this._remainingVacationDays = 20;
    }
}

class Nurse {
    constructor (name) {
        this._name = name;
        this._remainingVacationDays = 20;
        this.takeVacationDays(), this.addCertification()
    }
}

Be sure to close the body of the constructor. Not sure about the code, though. It doesn’t look quite right.

Moving the curly brace } from the end to the bottom of class got rid of the error.

class Doctor {
      ^^^^^^
SyntaxError: Unexpected identifier
class HospitalEmployee {
  constructor (name) {
    this._name = name;
    this._Doctor = Doctor;
    this._Nurse = Nurse;
    this._remainingVacationDays = 20;
}

get name() {
    return this._name;
  }

get remainingVacationDays() {
    return this._remainingVacationDays;
  }

takeVacationDays(daysOff) {
  _remainingVacationDays -= daysOff
}

class Doctor {
    constructor (name) {
        this._name = name;
        this._remainingVacationDays = 20;
    }
}
class Nurse {
    constructor (name) {
        this._name = name;
        this._remainingVacationDays = 20;
        this.takeVacationDays(), this.addCertification()
    }
}

The HospitalEmployee class is missing the closing brace.

Are those meant to be methods on that class? They need to be declared as such.

class HospitalEmployee {
  constructor(name) {
    this._name = name;
    this._remainingVacationDays = 20;
  }
  
  get name() {
    return this._name;
  }

  get remainingVacationDays() {
    return this._remainingVacationDays;
  }
  
  takeVacationDays(daysOff) {
    this._remainingVacationDays -= daysOff;
  }
}

Here’s the answer to question one.

Here’s the answer to the remaining question and how to solve them step by step. What I did was I answer each question step by step how it was asked.