How do you use state design patterns?

This series covers explanation and examples of the most important and commonly used JavaScript Design Patterns. JavaScript modules are the most prevalently used design patterns for keeping particular pieces of code independent of other components . This provides loose coupling to support well-structured code.

A state machine, per the academic definition, is any abstract machine that can be in exactly one of a finite number of states at a given time . A state machine should concern itself with the behavior of an isolated, discrete component or piece of logic. For example, a Promise is a state machine.

State is a behavioral design pattern that allows an object to change the behavior when its internal state changes . The pattern extracts state-related behaviors into separate state classes and forces the original object to delegate the work to an instance of these classes, instead of acting on its own.

Design patterns in JavaScript are reusable solutions applied to commonly occurring problems in writing JavaScript web applications . It is quite appropriate to refer JavaScript design patterns as templates to provide solutions to problems but not quite to say that these patterns can replace the developers.