What Is Currying In Programming?

Table of contents

• What is Currying?
• Key Features of Currying
• Currying Example (Javascript)
• Real-World Uses of Currying

What is Currying?

Currying is a way to transform a function [→] so that it takes one argument [→] at a time. Instead of taking all arguments at once, a curried function takes the first argument and returns a new function that takes the next argument, and so on. This can make your code cleaner and more flexible.

Key Features of Currying

Currying has some key features:

1. One Argument at a Time: Functions take arguments one by one.
2. Function Chaining: Each function returns a new function until all arguments are provided.
3. Reusable Functions: You can create reusable functions with preset arguments.

Currying Example (Javascript)

In JavaScript, you can create a curried function like this:

✅ Wrap📋
01: function curry(func) {
02:     return function curried(...args) {
03:         if (args.length >= func.length) {
04:             return func.apply(this, args);
05:         } else {
06:             return function(...nextArgs) {
07:                 return curried.apply(this, args.concat(nextArgs));
08:             }
09:         }
10:     };
11: }

Example of Currying a Function

Let's look at an example:

✅ Wrap📋
01: function add(a, b) {
02:     return a + b;
03: }
04: 
05: let curriedAdd = curry(add);
06: 
07: console.log(curriedAdd(1)(2)); // Output: 3

In this example, curriedAdd(1) returns a new function that takes the second argument, and curriedAdd(1)(2) returns the sum.

Real-World Uses of Currying

Currying is used in many situations, like:

1. Function Composition: Creating complex functions by combining simpler ones.
2. Partial Application: Pre-setting some arguments for a function.
3. Event Handling: Simplifying event handlers in web development.
4. Data Transformation: Creating pipelines for data processing.

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