Object.defineProperty() vs Object.prototype.property vs Object.property when to use what?

Question

Can somebody give me a good use case of when to use Object.defineProperty(), Object.prototype.property and Object.property.

Carlita

What exactly do you mean by "Object.prototype.property"? There is no such property. Are you asking "when to use the prototype?" or "when to put a property on Object.prototype" or "What's the difference between putting properties on the prototype and on the constructor?"? – Sherbet

You might be looking for Why is it Object.defineProperty() rather than this.defineProperty()? or Object.defineProperty vs vanilla property regarding defineProperty. – Sherbet

Possible duplicate of Object.defineProperty or .prototype? – Bering

Answer 1

Imagine we have a person object with an age property with a value of 20.

The Object.defineProperty() method defines a new property directly on an object, or modifies an existing property on an object, and returns the object.

Object.defineProperty(obj, prop, descriptor)

How is this different than the normal assignment operator?

It gives you more control over creating a property than standard assignment (person.age = 25). On top of setting the value, you can specify whether a property can be deleted or edited among other things outlined in more detail here Object.defineProperty() page.

A few examples

To add an name field to this person that cannot be changed with an assignment operator:

Object.defineProperty(person, "name", {value: "Jim", writable: false})

or to update the age property and make it editable:

Object.defineProperty(person, "age", {value: 25, writable: true}) .

Object.prototype.property and Object.property both refer to accessing a property of an object. This is like accessing the age property of the person object using person.age (you can also use person["age"])

Vachell

Neither "Jim" nor 25 are descriptors. – Sherbet

So what's the use case? why not simply person.age = 25? – Sherbet

It gives you more control over creating a property than the standard person.age = 25. On top of setting the value, you can specify whether a property can be deleted or edited among other things. – Vachell

Yeah, please put that in your answer, that's what the OP wants to know :-) – Sherbet