Converge Branching Functions

Introduction

In this lab, we will explore the concept of converge branching functions in JavaScript. The purpose of this lab is to help you understand how to create a higher-order function that accepts a list of branching functions and a converging function as arguments and returns a new function that applies each branching function to the arguments and passes the results to the converging function. This technique can be useful in many scenarios where you need to combine multiple functions to produce a final result.

Skills Graph

Converging Functions

To practice coding, open the Terminal/SSH and type node.

This function converge takes a converging function and a list of branching functions as input. It returns a new function that applies each branching function to the input arguments. The results of the branching functions are then passed as arguments to the converging function.

The Array.prototype.map() and Function.prototype.apply() methods are used to apply each function to the input arguments. The spread operator (...) is then used to call converger with the results of all other functions.

Here's the code for the converge function:

const converge =
  (converger, fns) =>
  (...args) =>
    converger(...fns.map((fn) => fn.apply(null, args)));

An example of how to use this function is shown below. The average function is created by calling converge with an anonymous function that calculates the average of an array. The branching functions are two anonymous functions that calculate the sum of an array and its length, respectively.

const average = converge(
  (a, b) => a / b,
  [(arr) => arr.reduce((a, v) => a + v, 0), (arr) => arr.length]
);
average([1, 2, 3, 4, 5, 6, 7]); // 4

This code calculates the average of the array [1, 2, 3, 4, 5, 6, 7] and returns 4.

Summary

Congratulations! You have completed the Converge Branching Functions lab. You can practice more labs in LabEx to improve your skills.