What is Reducers

What is Reducers in React.Js and React Native?

Reducers in React.Js and React Native are functions that specify how the application’s state changes in response to actions. They take the current state and an action as arguments, and return a new state based on the action type. Reducers are a key concept in Redux, a popular state management library used in React applications.

Reducers are pure functions, meaning they do not modify the state directly. Instead, they create a new state object and return it. This makes reducers predictable and easy to test, as they always produce the same output for the same input.

In React.Js and React Native, reducers are typically combined into a single root reducer using the combineReducers function provided by Redux. This root reducer is then passed to the createStore function to create the application’s store, which holds the state tree.

When an action is dispatched in a React application, it is sent to the root reducer, which delegates the action to the appropriate reducer based on the action type. The reducer then updates the state accordingly and returns the new state to be stored in the store.

Reducers in React.Js and React Native play a crucial role in managing the application’s state in a predictable and efficient manner. By following best practices and keeping reducers pure and focused on a single slice of state, developers can maintain a clear and maintainable codebase.

In summary, reducers in React.Js and React Native are functions that specify how the application’s state changes in response to actions. They are pure functions that create a new state object based on the action type, making them predictable and easy to test. By combining reducers into a root reducer and following best practices, developers can effectively manage the state of their React applications.