React Redux is a library that is used to manage the state of a React application. It is a combination of two libraries, React and Redux. React is a JavaScript library for building user interfaces, while Redux is a library for managing the state of an application.
The main concept behind React Redux is the store. The store is where the state of the application is kept and it can be accessed and updated by different components in the application. The store is created using the Redux createStore() function and it takes a reducer as an argument. The reducer is a function that takes the current state and an action as input and returns a new state.
To connect a React component to the store, the connect() function from the react-redux library is used. This function takes two arguments, a mapStateToProps function and a mapDispatchToProps function. The mapStateToProps function is used to map the state from the store to the props of the component, while the mapDispatchToProps function is used to map the actions that the component can dispatch to the props of the component.
When a component is connected to the store, any updates to the state in the store will cause the component to re-render. This makes it easy to keep the state of the application in sync with the user interface.
The actions in a React Redux application are plain JavaScript objects that have a type property and can have additional properties depending on the action. These actions are dispatched to the store using the dispatch() method and the reducer function in the store will handle the action and update the state accordingly.
The key advantage of using React Redux is that it helps to keep the state of the application separate from the components. This allows for better code organization and easier debugging. It also allows for more predictable behavior of the application, as the state is kept in a single location and is updated in a consistent way.
In conclusion, React Redux is a powerful library that allows for easy management of the state in a React application. It provides a clear separation of concerns between the state and the components, making it easier to build and maintain large-scale web applications. It also helps to keep the state of the application in sync with the user interface, which leads to more predictable behavior and a better user experience.