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JavaScript Object-Oriented JavaScript (2015) Prototypal Inheritance Setting Up the Prototype Chain

Joseph Frazer
Joseph Frazer
5,404 Points
Posted by Joseph Frazer
Joseph Frazer
5,404 Points

Stuck with this question.

Please help. I am really confused with what to do here.

person.js 
function Person(firstName, lastName) {
  this.firstName = firstName;
  this.lastName = lastName;
}

Person.prototype.fullName = function() {
 return this.firstName + " " + this.lastName; 
};
teacher.js 
function Teacher(firstName, lastName, roomNumber) {
  Person.call(this, firstName, lastName);
  this.firstName = firstName;
  this.lastName = lastName;
  this.room = roomNumber;
}

1 Answer

Lucas Santos
Lucas Santos
19,315 Points
Lucas Santos
Lucas Santos
19,315 Points

Hey Joseph,

All you need to do is remove 

  this.firstName = firstName;
  this.lastName = lastName;

from within the teachers constructor.

This is because the call method already assigns this.firstName and this.lastName. So your teachers constructor should look like this.

function Teacher(firstName, lastName, roomNumber) {
  Person.call(this, firstName, lastName);
  this.room = roomNumber;
}