Purpose of Reducers in Redux

In Redux, reducers play a crucial role in managing how the state of an application is updated in response to actions. They are pure functions responsible for specifying how the state transitions from one state to another based on the actions that are dispatched.

Here’s a detailed explanation of the purpose and functionality of reducers in Redux:

1. Handling State Transitions

Reducers define how the application's state changes in response to actions. An action is dispatched to indicate some event or interaction in the application (such as a user clicking a button, a form being submitted, or an API request returning data). The reducer listens for these actions and updates the state accordingly.

A reducer typically takes two arguments:

• state: The current state of the application (or a slice of the state).
• action: An object representing the dispatched action, usually containing a type and an optional payload.

The reducer returns a new state based on the action type, without modifying the current state directly (i.e., immutability is maintained).

Example:

const initialState = { counter: 0 };

const counterReducer = (state = initialState, action) => {
  switch (action.type)…