CODEWITHSUNDEEP
javascript
Darya Balu
Darya Balu

Reputation: 149

DefineProperty method is undefined in object created via constructor

I have a constructor for parent:

function genshinImpactCharacter(weapon, vision, rarity) {
    this.weapon = weapon;
    this.vision = vision;
    this.rarity = rarity;
}

Later I create an object with the new keyword:

const Sucrose = new genshinImpactCharacter('Catalyst', 'Anemo', 4);

I am trying to use defineProperty to add property favFlower: "Sweet Flower"

Object.defineProperty(Sucrose, "favFlower", {
    name: 'Sweet Flower',
});

However, when I am trying to access favFlower, it returns undefined. As well, when I print the whole object in the console, this property remains undefined.

Where did I make the mistake?

Upvotes: 0

Views: 276

Answers (1)

connexo
connexo

Reputation: 56770

You need to make the property enumerable (which defaults to false) to see it when inspecting the object. Also you want to set value of the property, not name:

function genshinImpactCharacter(weapon, vision, rarity) {
    this.weapon = weapon;
    this.vision = vision;
    this.rarity = rarity;
}

const Sucrose = new genshinImpactCharacter('Catalyst', 'Anemo', 4);

Object.defineProperty(Sucrose, 'favFlower', {
    value: 'Sweet Flower',
    enumerable: true,
});

console.log(Sucrose);

Please also note that by default properties added with Object.defineProperty() are not writable (writable: false again is the default), so with the current code you cannot assign to the property later. Trying to do so will fail silently in non-strict mode, and throw an error in strict mode.

As a last note, by default properties added with Object.defineProperty() are not configurable (configurable: false again is the default), so with the current code you cannot delete the property or change it using Object.defineProperty() on that object with the same property name again. Trying to do so will fail silently in non-strict mode, and throw an error in strict mode.

For more information, please consult https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/defineProperty

Upvotes: 4

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