React Design Patterns and Best Practices - Second Edition

Currying

A common technique in FP is currying. Currying is the process of converting a function that takes multiple arguments into a function that takes one argument at a time, returning another function. Let's look at an example to clarify the concept.

Let's start with the add function we have seen before and transform it into a curried function.

Instead of writing the following code:

const add = (x, y) => x + y;

We define the function as follows:

const add = x => y => x + y;

And we use it in the following way:

const add1 = add(1);add1(2); // 3add1(3); // 4

This is a pretty convenient way of writing functions because, since the first value is stored after the application of the first parameter, we can reuse the second function multiple ...