Why defining properties in the prototype is considered an antipattern

Question

I often see this pattern to define javascript objects

function Person(name) {
    this.name = name;
}
Person.prototype.describe = function () {
    return \"         


        

Answer 1

Perhaps related: In general modifying an object that you don't own is considered an anti pattern.

Meaning, if you didn't create the object then you don't "own" that object. Including:

• Native objects (Object, Array, etc)
• DOM objects
• Browser Object Model (BOM) objects (such as window)
• Library objects

Source Maintainable Javascript by Nicholas C. Zakas