Currying - jellyfish-tom/TIL GitHub Wiki

[SOURCES]

• https://en.wikipedia.org/wiki/Currying

This is not going to be about Horse Grooming.

In mathematics and computer science, currying is the technique of translating the evaluation of a function that takes multiple arguments into evaluating a sequence of functions, each with a single argument.

In JS it is achieved with closures.

//Instead of this:
function multiply(a, b) {
  return a * b;
}

const x = multiply(1, 2);

//We can do this:
function curriedMultiply(a) {
  return function(b) {
    return a * b;
  }
}

const y = curriedMultiply(1)(2);
//or
const multiplyByOne = curriedMultiply(1);
const z = multiplyByOne(2);

//and

x === y === z //true, all have value 2