Class vs Function

Classes and constructor functions are both used to create objects.

Classes are syntactic sugar over constructor functions and prototypal inheritance, providing a more readable and structured approach.

Function (Functional approach)

• Before classes were introduced, objects and their "types" were created through constructor functions.
• A function is used as a template to create objects when called with the new operator.
• Methods are added manually via the prototype property.
• This approach remains valid but is considered low-level and less readable compared to classes.

Class (Class approach)

• Classes are syntactic sugar over constructor functions and prototypal inheritance.
• They make code declarative, readable, and predictable.
• They define a template with a set of properties and methods, and support inheritance via extends.
• They are not hoisted like functions and always execute in strict mode.

Key Differences

• A class is a modern and convenient form of constructor functions.
• Classes have built-in support for inheritance and methods.
• Constructor functions require manual binding of methods via prototype.
• Classes cannot be called as a regular function without new.

In other words, classes are a structured and safe way to create objects, while constructor functions are a more raw mechanism underlying this system.