Currying

JavaScriptMiddle~1 min read

Currying is the process of transforming a function that takes several arguments into a sequence of functions, each of which takes only one argument.

Example:

A regular function:

javascript

function sum(a, b) {
  return a + b;
}

sum(2, 3); // 5

After currying:

javascript

function curriedSum(a) {
  return function (b) {
    return a + b;
  };
}

curriedSum(2)(3); // 5

How it works:

curriedSum(2) returns a new function that "remembers" the value a = 2.
That function then waits for the second argument b.
When we call it with 3, it returns the result 2 + 3.

Why currying is needed:

Reusing partially applied functions

javascript

const add10 = curriedSum(10);
add10(5); // 15
add10(7); // 17

Simplifies function composition - useful in functional programming.
Improves code readability and flexibility, especially in libraries like Lodash or Ramda.

In short:

Currying turns the function f(a, b, c) into f(a)(b)(c), so it can be called in parts and partial calls can be reused.

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Currying

#Example:

#How it works:

#Why currying is needed:

#In short:

Short Answer

Example:

How it works:

Why currying is needed:

In short: