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JavaScript Object-Oriented JavaScript Getters and Setters Setters

Peter Retvari
Peter Retvari
Full Stack JavaScript Techdegree Student 8,392 Points

Where exactly we use the owner parameter inside: set owner (owner)?

Hi guys,

For me the 1 and only parameter is confusing a little in this part, when we create the setter method:

 set owner (owner) {

Later when the user type the value of the given property (owner), she/he has to write:

ernie.owner = 'Peter';

I understand that we set the value of an object like this: objectname.dot = 'XY', but if we set like this, why we need the owner parameter in this code:

 set owner (owner) {

Because in other cases when we set a parameter inside the parenthesis:

class Pet {

  constructor (animal, age, breed, sound) {

    this.animal = animal;
    this.age = age;
    this.breed = breed;
    this.sound = sound;


We used it later like this (gave the values of the Barney object properties) :

const Barney = new Pet ('bird', 2, 'nice bird');

1 Answer

Steven Parker
Steven Parker
216,133 Points

I understand your confusion. A setter is a bit different from a typical method in that the syntax for using it looks like an assignment instead of a method call. This is intentional to make it consistent with setting a value in a field, and a complement to the syntax of a getter which also mimics getting a value from a field.

As an alternative, you can always create a conventional method that performs the same job and call it instead.