Redux is a predictable state container for JavaScript apps. As the application grows, it becomes difficult to keep it organized and maintain data flow. Redux solves this problem by managing application’s state with a single global object called Store. Redux fundamental principles help in maintaining consistency throughout your application, which makes debugging and testing easier.

Principles of Redux

Predictability of Redux is determined by three most important principles as given below −

Single Source of Truth

The state of your whole application is stored in an object tree within a single store. As whole application state is stored in a single tree, it makes debugging easy, and development faster.

State is Read-only

The only way to change the state is to emit an action, an object describing what happened. This means nobody can directly change the state of your application.

Changes are made with pure functions

To specify how the state tree is transformed by actions, you write pure reducers. A reducer is a central place where state modification takes place. Reducer is a function which takes state and action as arguments, and returns a newly updated state.

see several benefits that are commonly discussed:

• Predictable state updates make it easier to understand how the data flow works in the application

• The use of "pure" reducer functions makes logic easier to test, and enables useful features like "time-travel debugging".

• Centralizing the state makes it easier to implement things like logging changes to the data, or persisting data between page refreshes