ReactJS Q & A


What is Redux?

Redux is a widely-adopted state management library designed to maintain the global state of JavaScript applications, most commonly used in tandem with React. At its heart, Redux provides a consistent environment to store and manage the state of your application in a centralized location called the “store.”

The philosophy behind Redux emphasizes three core principles. First, there is a single source of truth; the entire state of the application is stored in one place, the aforementioned store. This centralized approach simplifies state management and makes debugging and state inspection more straightforward.

Second, the state is read-only. Direct modifications to the state are prohibited. Instead, to enact changes, you dispatch “actions.” Plain JavaScript objects that describe what change should occur. These actions signal the intention to transition from one state to another.

The third principle revolves around the use of pure functions called “reducers” to handle state changes. Given the current state and an action, a reducer will determine how the state should change in response. By always producing the same output state for a given input state and action, reducers ensure predictable behavior.

The workflow in Redux follows a cyclical pattern. User interactions or other events in the application dispatch actions. These actions are then processed by reducers, which compute the new state. Upon state update, the UI (often a React component) will reflect this new state, providing a reactive feedback loop.

One of Redux’s standout features is its developer tooling, which offers capabilities like time-travel debugging, allowing developers to step forward and backward through the state changes of their application. This, combined with the deterministic nature of reducers, makes troubleshooting considerably more manageable.

Redux offers a structured approach to global state management. Through its principles and mechanisms, it ensures that state changes in large-scale applications are handled predictably and transparently, leading to robust and maintainable applications.