January 12, 2019

Saturday Solutions #1

Today I will be breaking down different approaches for solving the code challenge in Sunday Studies #1. I will start with using fundamental JavaScript skills and then build up to more modern techniques with ES6+.

Recap: The Problem

The challenge for this problem is to take two different arrays (i.e., fruits and desserts) and merge the items into a new array called sweetStuff.

var fruits = [
    { name: "apple", quantity: 5 },
    { name: "grapes", quantity: 8 },
    { name: "pear", quantity: 2 },
    { name: "mango", quantity: 10 },
    { name: "watermelon", quantity: 2 }

var desserts = [
    { name: "cookie", quantity: 12 },
    { name: "cake", quantity: 1 },
    { name: "candy", quantity: 25 },
    { name: "cinnamon roll", quantity: 48 }

var sweetStuff = []


CodePen - Sunday Studies #1: Problem


Starting with the Basics

The first thing that pops into my head when confronted with a problem with iterating over items and manipulating them for some kind of action is looping. So as far as pseudo coding goes, the solution goes something like this:

  1. Loop through the fruits array
  2. For every fruit item, add it into sweetStuff
  3. Loop through the desserts array
  4. For every dessert item, add it into sweetStuff

Here's what it would look like with JavaScript (ES5).

// Loop through the fruits array
for (var i = 0; i < fruits.length; i++) {
    var fruit = fruits[i]

    // Push the fruit item to sweetStuff

// Loop through the desserts array
for (var i = 0; i < desserts.length; i++) {
    var fruit = desserts[i]

    // Push the fruit item to sweetStuff

CodePen - Sunday Studies #1: Solution (Basics)

Is this the most efficient code? No, but it gets you from zero to one. And when it comes to solving problems (especially in a technical interview), just go with your gut and show that you can solve the problem with no frills.

The Concat Method

As with any programming language, the next step past the fundamental method is to learn what built-in functions help to with common scenarios such as this. So for those who haven't encountered it before, you'll definiteely want to check out the concat array method.

TLDR; Concat allows you to create a new array by taking one array and adding the items of another array into it.

So the solution would look like this:

sweetStuff = fruits.concat(desserts)

CodePen - Sunday Studies #1: Solution (Concat)

ES6+ Method

If the goal is to practice using ES6+ features, the one that should come to mind for this one the spread operator.

TLDR; Take the items from an array / object and copies them into the new array / object

sweetStuff  = [...fruits, ...desserts]

CodePen - Sunday Studies #1: Solution (Spread)

Extra Credit

When I first wrote this code challenge, I thought that the ES6 method would be the answer to the extra credit. Upon closer inspection though, it turns out the concat method is shorter by two characters!

Final Thoughts

As I continue to iterate on this series, please feel free to reach out with requests and/or feedback. You can either reach out to me directly on Twitter or open a new issue. Thanks for reading!