What's the difference between class-based and prototype-based programming?

Class-based programming uses predefined classes to create objects, while prototype-based programming creates objects then adds properties and methods.

In class-based programming, a class is a blueprint from which individual objects are created. Each object is an instance of a class, and each class encapsulates data and methods that are common to all objects of that class. For example, a 'Car' class might define properties such as 'colour' and 'model', and methods such as 'drive' and 'park'. When a new 'Car' object is created, it automatically has these properties and methods. This approach is used in languages such as Java, C++, and Python. Additionally, class-based languages typically make use of standard algorithms to handle data and operations efficiently.

On the other hand, prototype-based programming is a style of object-oriented programming in which classes are not present, and behaviour reuse (known as inheritance) is performed via a process of cloning existing objects that serve as prototypes. This model can be more flexible than class-based programming, as it allows for properties and methods to be added to individual objects, or to the prototype that defines a type of object. JavaScript is a well-known language that uses prototype-based programming.

In prototype-based programming, every object is essentially a clone of another object and can therefore inherit properties and methods from the prototype. For example, in JavaScript, you might start with a basic 'Car' object, and then create a 'Ford' object that inherits the properties and methods of the 'Car' object, but also has additional properties and methods that are specific to 'Ford' cars. This flexibility is central to the core principles of object-oriented programming which can be differently implemented in prototype-based languages.

A-Level Computer Science Tutor Summary: Class-based programming uses predefined classes to create objects, making it structured and consistent, used in languages like Java and Python. Prototype-based programming, seen in JavaScript, creates objects directly and allows for more flexibility by cloning existing objects and adding properties and methods. Both approaches are used in object-oriented programming to manage and reuse code effectively.