Exploring the Power of Reducer in React with TypeScript

March 4, 2024Author: Fabio J Raminhuk

Are you a frontend developer diving into the world of React with TypeScript? If so, you've likely encountered the term "reducer" and wondered what it's all about. In this guide, we'll explore the concept of reducers in React applications, specifically focusing on how to harness their power while utilizing TypeScript.


Understanding Reducers in React

Reducers are functions in React that take in the current state and an action, and return a new state based on that action. They are commonly associated with state management libraries like Redux, but React also provides a useReducer hook as a built-in alternative.


Advantages of Using Reducer

  1. Predictable State Updates: Reducers enforce a predictable pattern for updating state, making it easier to understand how data flows through your application.
  1. Centralized Logic: By encapsulating state updates within reducers, you can centralize your state management logic, leading to cleaner and more maintainable code.
  1. Type Safety with TypeScript: When using TypeScript, reducers provide additional benefits by allowing for strict typing of state and actions, preventing common runtime errors.

Example: Using Reducer in React with TypeScript

import React, { useReducer } from 'react';

// Define the type for our state
interface CounterState {
  count: number;

// Define the type for our actions
type Action = { type: 'increment' } | { type: 'decrement' };

// Define the reducer function
const reducer = (state: CounterState, action: Action): CounterState => {
  switch (action.type) {
    case 'increment':
      return { count: state.count + 1 };
    case 'decrement':
      return { count: state.count - 1 };
      throw new Error('Unhandled action type');

// Our Counter component
const Counter: React.FC = () => {
  const [state, dispatch] = useReducer(reducer, { count: 0 });

  return (
      Count: {state.count}
      <button onClick={() => dispatch({ type: 'increment' })}>Increment</button>
      <button onClick={() => dispatch({ type: 'decrement' })}>Decrement</button>

export default Counter;

In this example, we define a simple counter component that manages its state using a reducer. We specify the types for both state and actions, ensuring type safety throughout our component.


Video Overview: Reducer in React (Not Created by Me)

For those who prefer learning through visual content, here's an insightful video about using reducers in React with TypeScript. This video wasn't created by me, but it's a valuable supplement to our written content.



Reducers play a crucial role in state management within React applications, offering a predictable and centralized way to update state. When combined with TypeScript, reducers provide additional benefits in terms of type safety and code maintainability. By understanding and utilizing reducers effectively, you can enhance the scalability and robustness of your React projects.


Start integrating reducers into your React components today, and experience the benefits firsthand! Happy coding! 🚀