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

Anthony Scott
PLUS
Anthony Scott
Courses Plus Student 9,001 Points

getting conflicting errors

when I put person.call(this, firstName, lastName) in the code I get an error that says I don't need to put firstName, lastName in the code. When I remove those two, it gives me an error that says it needs this, firstName, lastName in that order. ???

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 = firstName;
  this.lastName = lastName;
  this.room = roomNumber;
}

1 Answer

Samuel Ferree
Samuel Ferree
31,722 Points

ah, okay the error message is a bit confusing. it's saying you don't need to set firstName and lastName in the teacher constructor, because you do need to pass them to the person constructor.

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