The Bloggo

State Management with Currying in React.js


Currying is a functional programming technique that transforms a function with multiple arguments into a sequence of nesting functions. Each function takes a single argument and returns another function that takes the next argument, and so on. This concept can be particularly useful in React for handling events and passing data.

Why Use Currying in React?

In React, currying can help improve the readability and maintainability of your code. It allows you to partially apply functions and create more specific handlers without the need to repeatedly pass all arguments.

Currying in JavaScript

Currying is a process of transforming a function that takes multiple arguments into a sequence of functions, each with a single argument. Here’s a simple JavaScript example:

In this example, the add function takes two arguments, a and b. Currying creates a new function, add5, that’s pre-configured with a=5. When called with 3, it returns the sum of 5 and 3.

Without Currying (Traditional Form Handling)

Consider a simple registration form with name and email fields in React:

Here, we have separate handleNameChange and handleEmailChange functions to update the respective state values. This approach works well for simple forms, but it can become cumbersome with many input fields, leading to code duplication.

With Currying (Refactoring with Currying)

Let’s leverage currying to create a more streamlined and reusable solution:

In this refactored version, we define a single handleChange function that takes two arguments:

  1. fieldName: A string representing the field name (e.g., “name”, “email”).
  2. event: The event object from the onChange handler.

handleChange returns another function that uses conditional logic to update the appropriate state value based on the fieldName. When we pass this returned function as the onChange handler for each input, currying allows us to pre-configure the fieldName argument. Now, a single handleChange function handles both name and email changes, reducing code duplication.

Benefits of Currying

  • Reduced Code Duplication: Currying eliminates the need for separate event handlers for each state variable, resulting in cleaner and more maintainable code.
  • Improved Readability: With a single, well-named function like handleChange, the code becomes easier to understand, especially in components with multiple input fields.
  • Encapsulation: Logic for updating different parts of the state is encapsulated within handleChange, promoting better organization.
  • Flexibility: Curried functions can be further customized to handle more complex state


Currying in React enhances state management by providing a structured, clear, and concise approach. It not only simplifies the code but also improves its readability and maintainability, making it an essential technique for React developers.

Subscribe to Porto newsletter and stay updated.

Don’t miss anything. Get all the latest posts delivered straight to your inbox. It’s free!

Subscription Form
Scroll to Top