Higher-Order Functions - Exploring the Power of Higher-Order Functions in JavaScript

Higher Order Function - 

A function that takes another function as an argument and/or returns a function from it is known as a higher-order function.

Let's learn the difference between the Normal function and the Higher-order function 

• The Traditional Approach: Normal Functions

Before we explore higher-order functions, let's take a look at the traditional approach to calculating the area, circumference, and diameter of an array of radius using normal functions.

const radius = [3, 1, 2, 4];

//Area

const calculateArea = function(radius){

  const output = [];

    for(let i = 0; i < radius.lenght; i++){

      output.push( Math.PI * radius[i] * radius[i] )

   }

  return output;

}

console.log(calculateArea(radius));

// Circumference

const calculateCircumference = function(radius){

    const output = [];

    for(let i= 0; i < radius.length; i++){

        output.push( 2 * Math.PI * radius[i] )

    }

     return output;

}

console.log(calculateCircumference(radius));

// Diameter

const calculateDiameter = function(radius){

    const output = [];

    for(let i= 0; i < radius.length; i++){

        output.push( 2 * radius[i] )

    }

     return output;

}

console.log(calculateDiameter(radius));

This approach works, but it involves repetitive code for each calculation, making it less maintainable and harder to read.

• The Modern Approach: Higher-Order Functions

Now, let's explore a more elegant and efficient solution using higher-order functions in JavaScript.

const radius = [3, 1, 2, 4];

// Helper functions

const area = function(radius){

    return Math.PI * radius * radius;

}

const circumference = function(radius){

    return 2 * Math.PI * radius;

}

const diameter = function(radius){

    return 2 * radius;

}

// Higher-order function

const calculate = function(radius, logic){

    const output = [];

    for(let i= 0; i < radius.length; i++){

        output.push(logic(radius[i]))

    }

    return output;

}

console.log(calculate(radius, area));

console.log(calculate(radius, circumference));

console.log(calculate(radius, diameter));

In this modern approach, we define three helper functions for area, circumference, and diameter calculations. Then, we create a higher-order function called calculate, which takes an array of radius and a logic function as arguments. The calculate function iterates through the array of radius and applies the provided logic function to each element, resulting in a concise and reusable code.