As mentioned by previous commenters and the articles they have shared, differential inheritance refers to a specific type of inheritance that deviates from the traditional prototypical inheritance model commonly seen in JavaScript.
In this approach, rather than relying on constructors and the new keyword, objects are created using Object.create, inheriting directly from another object in a single step. This method emphasizes creating only the properties that are different from the parent object manually, without the use of a constructor function. In essence, it allows for a more straightforward way to create instances without the need for dedicated prototype objects.
var object = Object.prototype;
// Creating a person object with instance properties
var person = Object.create(object);
person.greet = function() {
console.log("Hi, I'm "+this.firstName+" "+this.lastName);
};
// Creating an instance of person
var jo = Object.create(person);
jo.firstName = "John";
jo.lastName = "Doe";
// Another instance inheriting from jo
var ja = Object.create(jo);
ja.firstName = "Jane";
jo.greet(); // Output: Hi, I'm John Doe
ja.greet(); // Output: Hi, I'm Jane
While the traditional constructor pattern is widely used in JavaScript, adopting the pure differential inheritance pattern can provide a deeper understanding of object creation. Some experts suggest using Object.create extensively, as introduced in EcmaScript 5, to streamline the process.
Although the distinction between differential and prototypical inheritance may not be entirely clear-cut, exploring alternative inheritance methods can broaden your perspective on object-oriented programming.