How to uncurry a function in JavaScript

In this Article we will go through how to uncurry a function only using single line of code in JavaScript. This is a one-line JavaScript code snippet that uses one of the most popular ES6 features => Arrow Function.

Let's define this short function:

const uncurry = (fn, n = 1) => (...args) => (acc => args => args.reduce((x, y) => x(y), acc))(fn)(args.slice(0, n));

Parameters fn is a curried function.

Parameters n is the depth of parameters.

const sum = a => b => c => a + b + c;
uncurry(sum, 1)(1)(2)(3);       // 6
uncurry(sum, 2)(1, 2)(3);       // 6
uncurry(sum, 3)(1, 2, 3);       // 6