Using Array.reduce to transform data

The map method is great for creating data that maps directly to elements from an existing array. However, sometimes, the desired result takes on a different shape. To do this, we can use the reduce method to accumulate values into a new form.

In this recipe, we'll take a look at how to use the reduce method to transform data.

Getting ready

This recipe assumes that you already have a workspace that allows you to create and run ES modules in your browser. If you don't, refer to the first two chapters.

How to do it...

1. Open your command-line application, and navigate to your workspace.
2. Create a new folder named 10-05-reduce-to-transform-data.
3. Create a main.js file that defines a new class named Rocket that takes a constructor argument name and assigns it to an instance property:

// main.js 
class Rocket { 
  constructor(name) { 
    this.name = name; 
  } 
   } 

4. Create a main function with an array of nationality strings:

// main.js 
export function main() { 
  const...