DEV Community: w6

Javascript: Var vs Const vs Let 👍💯

w6 — Sat, 03 Sep 2022 20:43:37 +0000

A lot of shiny new features came out with ES2015 (ES6). And now, since it's 2022, it's assumed that a lot of JavaScript developers have become familiar with and have started using these features.

Var: Pros & Cons

A var (short for variable) is a global variable that can be accessed from anywhere, it is also able to be assigned different values.

var hello = "Hi!";

Pros:

It can be re-declared and updated
It's globally scoped (can be accessed from anywhere)

Cons:

It can be a pain to have to re-define other variables since it's globally scoped.

Const: Pros & Cons

Variables declared with the const maintain constant values. const declarations share some similarities with let declarations.

`Const` declarations are block scoped

Like let declarations, const declarations can only be accessed within the block they were declared.

`Const` cannot be re-declared or updated

This means the value set for a const will always stay the same and cannot be updated.

Pros:

It is block scoped
You can assign sub-variables like: const.message = "Hello" without issues.

Cons:

It cannot be re-declared or updated

const hello = "Hi!";
hello = "Ciao!" // Const cannot be updated.

Let: Pros & Cons

let is now preferred for variable declaration. It's no surprise as it comes as an improvement to var declarations. It also solves the problem with var that we just covered. Let's consider why this is so.

`let` is block scoped

So a variable declared in a block with let is only available for use within that block. Let me explain this with an example:

function test1() {
  let test = "ee";
  console.log(test); // returns "ee"
}

function test2() {
  let test = "ff";
  console.log(test); // returns "ff"
}

it can be updated but not re-declared

For example, this would return an error:

let test = "Hello!";
let test = "Robot."; // Error ❌

However, a let variable can be re-declared in different blocks. For example, a function and another function could use the same variable name without issue.

This makes let the primary choice for developers in 2022 since it's so easy-to-use and has a ton of upsides.

Pros:

Can be re-declared in different blocks
let is the modern version of var with a ton of improvements.

Cons:

It can be updated but it cannot be re-declared
Not much downsides since let is a great choice.

Thanks for reading 👋

If you like my content, please leave a ❤️ or even a Comment 💬

Creating Beautiful Pictures of Your Code! 🎨

w6 — Sat, 03 Sep 2022 17:27:09 +0000

What is Carbon?

Carbon as they say themselves, let's you "Create and share beautiful images of your source code."

You can turn your boring code into a beautiful image like this:

Why would I use it?

Let me ask you, which one of these looks better?

const pluckDeep = key => obj => key.split('.').reduce((accum, key) => accum[key], obj)

const compose = (...fns) => res => fns.reduce((accum, next) => next(accum), res)

const unfold = (f, seed) => {
  const go = (f, seed, acc) => {
    const res = f(seed)
    return res ? go(f, res[1], acc.concat([res[0]])) : acc
  }
  return go(f, seed, [])
}

OR:

If you picked #2 then Carbon is perfect for you! And if you picked #1, suit yourself!

How do I use it?

It's pretty simple! Head over to the Carbon website and just paste your code into the box!

Woah! Not that fast... 👀

Carbon also has a ton of themes that let you customize your image! Personally, I use "One Dark" for my images.

The End.

Thanks for reading my post, if you liked it, please leave a ❤️ or even a Comment 💬!

🔗 Carbon's Website

Editing and Deleting with MongoDB (Discord.JS)

w6 — Sat, 03 Sep 2022 17:10:14 +0000

Welcome 👋

First of all, if you haven't seen Part 1, you should read it or you may be confused. We're going to be using the same database that we created!

Editing & Saving Data

So, you want to edit data and save it to your database. Well, this is how you do that.

We're going to be changing the server's "key" to a new one! This is just an example but, you can use this for your own bot's functionalities.

Let's say that right now the server's "key" is ExampleLol123 and we want to change it to SuperSecretKey, this is how!

Start off by finding the server's entry by using the "FindOne" function.

Schema.findOne({ Guild: interaction.guild.id }, async (err, data) => {

});

Now that we've found the server's entry, let's change it's "key" to SuperSecretKey.

In the code below, we'll check if there is any data for the server then if there is, we'll change it.

if (data) {
  data["SpecialKey"] = "SuperSecretKey";
}

Finally, let's save it!

data.save();

Wasn't that easy? ☝️ Let's move on to deleting data!

Deleting Data 🗑

Let's say you want to delete a server's data (eg, if the bot was kicked from the server and you don't want to use up space), this is how!

We'll be using the handy findOneAndDelete function for this part of the tutorial. Basically, you'll find the entry and delete it all in 1 function! 😱

Schema.findOneAndDelete({ Guild: interaction.guild.id }, async (err, data) => {
});

If there's an error, we'll log that in the console 👇

if (err) {
   console.log(`❌Looks like there's an error: ${err}`);
}

Otherwise, if there isn't an error and everything is good, we'll make sure to log in the console that the operation was successful! ✅

else {
  console.log(`🍃 That was quick. Data deleted successfully! ✅`);
}

Learning More...

You've just learned how to 👀

Edit Data
Delete Data
and.. save it!

But if you want to learn more, please leave a ❤️ or a Comment 💬 to motivate me to make more of these tutorials!

Thank you for reading! 😃

Simple MongoDB Database Setup for Discord.JS (Replit)

w6 — Sat, 03 Sep 2022 04:13:35 +0000

Here's an easy implementation of MongoDB in a Discord.JS bot built on Replit! Be sure to follow the steps closely or you might miss something.

Requirements

1. You'll need discord.js installed of-course, I prefer using v14 but you can use an older version if you haven't upgraded yet.
2. Lastly, you'll need a MongoDB database set up. Make sure you have 0.0.0.0 whitelisted in the IP addresses so it will work with Replit.

🍃 MongoDB is a free database on the cloud that we'll use in this tutorial. It's very easy-to-use and it has a free tier!

Step 1

Create a "models" folder in your bot, we'll use this to store all the databases in.

Step 2

IMPORTANT: Create a environment variable called mongodb and put your database's connection URI in there. It should look something like this: mongodb+srv://username:password@cluster0.clusters.mongodb.net/?retryWrites=true&w=majority

Don't use the example I provided, put your own, it won't work. If you don't have a MongoDB, you can create on at MongoDB.

In your index.js file, include this:

const mongoose = require('mongoose');

mongoose.connect(process.env.mongodb, { useNewUrlParser: true, useUnifiedTopology: true }).then(console.log('Connected to Mongodb.'));

In the code above, we're connecting to your MongoDB database.

Step 3

Back to the models folder. Create a file in there with any name you want, I'll use "keys.js" for my example.

In the file, import the schema which you'll use later on.

const mongo = require('mongoose');

const Schema = new mongo.Schema({
  Guild: Number,
  SpecialKey: String
});

Here, we're specifying the basic schema that we'll use for the database. You can change this to fit your bot's functionalities.

Finally, export the schema as follows:

module.exports = mongo.model('yourdatabasename', Schema);

Add that to the bottom of the file! 😃

If you don't know how to make your own schema, you can view some examples here.

Step 4

This is the final step! Go to your bot's command cog you want to use the database in and follow these steps:

Import the database:

const Schema = require('../../models/keys.js'); // Example

Then in your command, you can fetch values as follows:

Schema.findOne({ Guild: interaction.guild.id }, async (err, data) => {
  if (data) {
    respond({"content": `This server's special key is: ${data["SpecialKey"]}!`});
  } else {
    new Schema ({
      Guild: interaction.guild.id,
      SpecialKey: "Examples ✨"
    }).save()

    respond({"content": `Woah! This server doesn't have a key yet 👀 I've just set yours to the default key instead!`});
  }
});

Editing and Deleting Data

If this post does well, I'll do a follow-up one with a tutorial on how to edit data, delete data and more.

Support Me

➡️ If you found this post helpful, please give it a 👍, Thank you!

How to get every item in an array for beginners.

w6 — Tue, 22 Dec 2020 16:54:50 +0000

Step 1: Create your array.

Create your array like this

  const MyArray = ["Item 1", "Item 2"];

Step 2: Create the Method1 function

Add a function that looks like this

 function method1(arr) {
   for (var i = 0; i < arr.length; i++) {
     console.log("Method 1: " + arr[i]);
   }
  }

And add this code to call the function:

  method1(MyArray);

Now open the index.html file and look in the console. It should say something like this:
If it does you successfully looped over an array and console logged it!

Aditional Methods:

If you want something more simple but slower than the traditional for loop you can try out these functions:

function method2(arr) {
  for (const e of arr) {
    console.log("Method 2: " + e)
  }
}
function method3(arr) {
  arr.map(e => e).forEach(e => {
    console.log("Method 3: " + e);
  })
}

Thanks for reading my first article!

DEV Community: w6

Javascript: Var vs Const vs Let 👍💯

Var: Pros & Cons

Pros:

Cons:

Const: Pros & Cons

Const declarations are block scoped

Const cannot be re-declared or updated

Pros:

Cons:

Let: Pros & Cons

let is block scoped

it can be updated but not re-declared

Pros:

Cons:

Thanks for reading 👋

Creating Beautiful Pictures of Your Code! 🎨

What is Carbon?

Why would I use it?

How do I use it?

The End.

Editing and Deleting with MongoDB (Discord.JS)

Welcome 👋

Editing & Saving Data

Deleting Data 🗑

Learning More...

Simple MongoDB Database Setup for Discord.JS (Replit)

Requirements

Step 1

Step 2

Step 3

Step 4

Editing and Deleting Data

Support Me

How to get every item in an array for beginners.

Step 1: Create your array.

Step 2: Create the Method1 function

Aditional Methods:

`Const` declarations are block scoped

`Const` cannot be re-declared or updated

`let` is block scoped