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JavaScript Essentials: A Beginner's Guide to Data Structures and Algorithms

Matt Ryan on December 05, 2023

If you're looking to get your JavaScript skills to the next level, you're in the right place. Let's jump right in! 🎉 What are Data Struct...

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CedricLapi • Dec 6 '23

i love the analogies you've used to explain these concepts, as a beginner i find it quite insightful!

Eckehard • Dec 6 '23 • Edited

Unlike structures in other languages, Javascript cannot limit the elements in an object in any way. This is especially bad because even const arrays can be extended:

const car = {
  make: "Toyota",
  model: "Corolla",
  year: 2021
};
car.color = "red"

Object.freeze(car);
car.fruit = "Bananna"

console.log(car) => {make: 'Toyota', model: 'Corolla', year: 2021, color: 'red'}

You can prevent extension by freezing the object, but you will not get an error message.

The only way I know to ensure that certain properties are defined ist this:

function setTemplate(target, template) {
    Object.keys(template).forEach(key => target[key] = target[key] ?? template[key])
}

const car = {
    make: "Toyota",
    model: "Corolla",
    year: 2021
};

const template = {
    make: "-",
    model: "-",
    year: "-",
    size: "-",
    length: "-"
}

setTemplate(car, template)

console.log(car) => {make: 'Toyota', model: 'Corolla', year: 2021, size: '-', length: '-'}

Mike Stemle • Dec 6 '23

I wish there were more detail. When would you use a structure? Where would you avoid its use? How are the structures more helpful than similar alternatives? Same for the algorithms.

Good stuff, it’s just missing a lot of detail.

Mike Talbot ⭐ • Dec 6 '23

Probably worth pointing out that binary search requires a sorted array.

Yeom suyun • Dec 6 '23

There seems to be a problem with the algorithm implementation in the code.
Even excluding minor optimizations, merge sort includes empty left and right in the return, while quicksort employs unnecessary left and right.