DEV Community: ProCode

Anonymise yourself! How to set up tor in mac? In the terminal - noob_sec series

ProCode — Sun, 18 Jul 2021 17:40:19 +0000

Hey all! Let me ask you a question. If I said to you I have a proxy server and if you pass your traffic through my servers I will keep your browser data encrypted and hide your IP and I will keep a record of your traffic. That is in layman's terms, I won't let anyone know what are you doing on the internet, only I will know. Would you trust me and accept my offer?

Or If my friend, lets call him John has another service. A decentralised peer to peer network where no such organisation/company keeps logs of your traffic and pretty much does the same thing. Helps you hide your IP and stuff.

Which service would you choose? mine or Johns? Let me guess, John's right? See! I'm already in your brain! But there's a caveat to John's service. They are a bit slow and the setup process is a bit of an hassle. That's why people still choose my service over John's. Because with my service, with 1 click you can be anywhere in the world, encrypt your browser history all that good stuff.

Well, maybe you have already figured out what are the two services I am talking about in the previous example. But if not, let me do the honours, They are VPNs(my service) and tor(John's service). Now, I am not encouraging or discouraging you to use one or the other services in question here. That's totally your choice. This article is just an introduction to tor and how you can get sneak peek of tor's powers. Keep in mind this will not be a complete setup with proxychains and stuff, just how to install mac and pass your traffic through tor so your IP is hidden. You can follow this tutorial if you don't have a mac as well. You'll just have to know how to install stuff from your package registry and how to add a proxy in your system.

Generally you can install tor browser and use that to get all the features of tor. But I want to pass all traffic of my system through tor and not only the requests that are made from the tor browser. For example, requests from the terminal as well.

Installation

I will be using Homebrew to install tor. if you do not have brew installed. Download it from here or run this command in your terminal.



/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

Now that we have brew, we can go ahead and install tor.
Run this command to install tor.



brew install tor

After the command has finished running, we should have tor installed in our system. Lets start the tor service now.
Run this command to start tor.



brew services start tor

If it ran successfully you should see and output like this:



==> Successfully started `tor` (label: homebrew.mxcl.tor)

Now let's verify if tor proxy is running or not. It by default runs on localhost:9050 so let's use netstat to verify that.



netstat -ant | grep 9050

If you see something similar to this, all good!



tcp4       0      0  127.0.0.1.9050         *.*        LISTEN

Now all we have to do is pass our traffic through this proxy. We'll see that in a moment but before that let's see what our IP address is right now. Google what is my ip or click in this link to do the same. Now lets pass our traffic through tor's proxy to see if our IP changes.

In your mac, open system preferences.

Then click on Network,

Then click on advanced, (also do that click on the lock and enter password thing if you have to.

Then click on the proxies tab,

Choose the SOCKS proxy from the check list and on the right side, enter localhost - 127.0.0.1 on the first input box and 9050 in the second which is for the port. Then click on Ok and then Apply.

AND we are done! Now if you Google what is my ip or click in this link to do the same! Did you see it? Because I did! That shows a different IP!

As I said in the beginning, tor is a bit slow for normal browsing, why? That might be a topic for another article but now the question is are you willing to use tor for normal browsing even if it's slow? No right? Yeah me too. But after watching that crazy youtube conspiracy video of governments spying on people, when your paranoia hits, you can just turn on tor! or maybe for other stuff. Don't use it for bad practices obviously, you'll be an idiot if you do so.

Let me get you started with this paranoia thing a little bit so you can use tor right away 😂. Sure VPNs hide your IP, encrypt your browser history and stuff. But they do have log of all your browsing data. Why do you think they keep that? Why do you think VPNs were invented on the first place? hmm........

See you on another article!

Create template repositories from just a single JSON file! What is Dgen?

ProCode — Mon, 05 Jul 2021 18:25:27 +0000

Hey all! haven't written something in a while, so I thought I would put my thoughts together about a recent project I built called Dgen. This post might as well become a blog on how to create Dgen in rust. Let's keep writing!

What is it?

Dgen is a utility that converts repositories to a JSON file. So basically useful for your starter code repositories. Which you might be storing in Github right now as template repositories.

so let's say we have a directory that looks like this:

dgen-blog
├── assets
├── index.html
├── main.js
└── style.css

1 directory, 3 files

The JSON file that Dgen will generate for this directory will look like this:
dgen-blog.json

{
  "name":"dgen-blog",
  "files":[
            {
              "name":"index.html",
              "content":"<html lang=\"en\"..."
            },
            {
              "name":"main.js",
              "content":"console.log(..."
            },
            {
              "name":"style.css",
              "content":".body {\n..."
            }
          ],
  "folders":[
              {
                "name":"assets",
                "files":[],
                "folders":[]
              }
            ]
}

The shape of the JSON file will make sense in a moment I promise!

Is it useful?

Umm not sure, I am just experimenting with the idea. It works fine for most huge starter repositories. If you keep a collection of these JSON files locally, you would be able to generate you repositories offline without any hassle and also super fast!

How to install it?

For now, if you have rust installed you can clone the repository and run the following commands to generate the executable binary.

# clone the repo
$ git clone https://github.com/ProCode2/dgen.git

# get in the project diretory
$ cd dgen

# build the binary
$ cargo build --release

# check if its working
$ ./target/release/dgen-rs -V

# for !windows
$ ln -s ./target/release/dgen-rs /usr/local/bin

How to use it?

You'd use the binary to either create a blueprint from a directory or create a directory from a blueprint.

Here's how to create a blueprint from a directory: Go inside the directory you want to create a blueprint of and run this command:

# creates a JSON blueprint
$ dgen-rs -b

You'd see a <directory_name>.json file will be created in your directory if the command runs successfully. Now you can store this JSON file wherever you are collecting all the JSON blueprints and forget about the directory, the JSON file can create it again anyways! Let's see how to do that now.

Here's how to create a directory from a blueprint: Go to the path where you will create the directory and run this command:

# creates a directory
$ dgen-rs -g /path/to/the/json/blueprint

The Shape of the JSON file

Here's the core idea - Every single directory has a name, few files with their contents, and a few folders with the same things mentioned above.(RECURSION!)

So the base json looks like this:


{
  "name":"",
  "files":[],
  "folders":[]
}

And it grows to a weird looking JSON file, which works.

Some issues with this concept

Currently the structure for storing files is this:

{
  "name": "main.js",
  "content": "console.log(......."
}

Which means, contents can store only valid utf-8 characters. So how do we store images, videos, audios or even binaries. I am not sure if any starter repository have any of those. But I still want to solve this, which is a problem I created on the first place lol. For the images I might store a base64 string in content? I am still thinking on this idea. Also I am open to suggestions as well! Let me know if you have any idea to solve this issue! or any comments on the project as well!

How to create `Dgen` in next article

Well If I keep adding how to create Dgen yourself in this article it will get pretty big! So I will be uploading a fresh new article on that topic! Stay tuned!

Thanks for reading!

How to use Qpython3 to code in python on a smartphone - UDAYANCARE CODING BOOTCAMP

ProCode — Sat, 19 Dec 2020 14:09:03 +0000

Hey curious people 👋, if you are looking for a way to write and run python code in your smartphone, you are just at the right place. let's see how we can do that!

Download Qpython3

First of all make sure you have downloaded the app Qpython3 in your smartphone. If you haven't yet click this link to download the app, or search for QPython 3L - Python for Android in play store. If you are using IOS, there are similar apps like Pythonista 3. Or you can also use a browser-based interpreter, but I will recommend that only for basic usage.

How to use?

let's get the basics done first! we'll first open the app, create a python file, write 3-4 lines of code, and run it. Let's see how to do that step by step.

Step 1 - Open the app and click on the editor

Now you'll see a screen like this(your theme/colours might be different):

Step 2 - Click on the second icon in the top right corner of your screen to add a file.

You'll see a screen like this once you do so:

Step 3 - Click on Script and name the file intro.py(Actually you can name the file whatever you want, just make sure to add the extension ".py" after the name of your choice) and press OK.

And now we have a file we can code in! Let's write some code and run it. Copy this code to your own file in the app.

#assigning 2 to variable x
x = 2

#assigning 3 to the variable y
y = 3

"""
adding x to y and storing the
result in variable z
"""
z = x + y

#printing variable z to console
print(z)

Now let's hit run and see what happens. The run button is the triangle in the middle in the lower options bar. There are other buttons too for saving the code, undo e.t.c.

After clicking run if you see this screen below which says 5(ignore all the other stuff), then we are good because 3 + 2 is indeed 5! Our code worked! And now we can write whatever code we want here, as we learn more.

Sliding Window Technique🔥

ProCode — Sat, 25 Jul 2020 18:38:38 +0000

Hey curious people👋! Have you ever felt so good after writing an algorithm that not only solves a problem but solves it efficiently? In this blog, we'll learn about an algorithm that'll help you get that feeling more often! Sliding Window Technique(SWT) - I understand this algorithm as one that helps improve the time complexity of a solution(generally for problems dealing with sequential and iterable data structures like an array) from O(N²) to O(N) and if you don't understand Time Complexity, just know that it helps improve your solution so that it runs faster.

What is SWT?

According to most definitions, SWT is a way of converting some brute force(mostly O(N²))) algorithms to a linear(O(N)) algorithm.

Is it helpful?

In an interview, improving an algorithm from O(N²) to O(N) is a great deal(well...at least for me😅).

How to do it?

To understand how to do it, let's look at a problem, at first we will think about a brute force solution and then improve it by applying SWT. Before that let me give you a basic idea of how we apply SWT(this might not make sense now, but definitely will during solving the problem!).
Let's suppose we have an array and we want to find the largest element in the array. The solution might be to look at every element and keep track of the largest element. To put it in the SWT way, it might look something like this:👇

Now you might have guessed it, The window slides(did it click?💡) from left to right, we look at the value check if it is the largest element we have seen and this continues until the window reaches the end of the array. The window might be of any size depending on the problem we are dealing with, it can be one(or any number of elements) elements long, or it can be of variable size. The window size can either be fixed or dynamic.

The Problem

Given an array of N positive integers, find the maximum sum of 3 consecutive elements

The brute force approach

The first solution that comes to my mind is to find every possible sub-array of 3 consecutive elements and find their sum and keep track of the maximum one. We'll need two nested loops for this, let's see this algorithm in code.

let arr = [1, 3, 5, 6, 2, 7, 8];
let maxSum = 0;  //to keep track of maximum sum.

for (let i = 0; i < arr.length - 3 + 1; i++){
  //Initializing sum
  let sum = 0;
  //Adding 3 elements starting from i
  for (let j = 0; j < 3; j++){
    sum = sum + arr[i + j];
  }
  //Storing the maximum sum
  maxSum = Math.max(sum,maxSum);
}

console.log(maxSum);

The Time Complexity of this algorithm is O(N*3), it could be worse if it was a bigger set of elements instead of 3.

The SWT approach

Now, let's see how the SWT approach works.

Now what we want to do is have a window of size 3, keep count of its sum and keep track of the maximum sum as it slides to right. Now let's visualise what will happen if the window moves one element to the right. What we are actually doing is adding the 4th element to the sum and subtracting the 1st element, and repeating the same until the window reaches the end of the array. Let's see how that will look like in code.

let arr = [1, 3, 5, 6, 2, 7, 8];
let maxSum = 0;  //to keep track of maximum sum.
let sumOfWindow = 0; //to keep track of sum of the window.
let windowSize = 0;

for (let i = 0; i < arr.length + 1; i++){
  if(windowSize == 3){
    console.log('current windows sum is');
    console.log(sumOfWindow);
    //storing the maximum sum
    maxSum = Math.max(maxSum, sumOfWindow);
    //deleting the end element of the window
    sumOfWindow = sumOfWindow - arr[i - 3];
    windowSize--;
  }

   //adding elements to the window.
  sumOfWindow = sumOfWindow + arr[i];
  windowSize++;

}

console.log("The maximum sum is: " + maxSum);

Voila! That's in a single loop, that means O(N) time complexity! ahem..To use fewer loops, use more brain aaaaand probably some more lines of code(not always).
There you have it! Sliding Window Technique!

When to use it?

I try to use it generally when I see problems that have something to do with consecutive elements of an iterable data structure like arrays or strings(For ex: max continuous subarray, longest non-repeating substrings).

Now that you know about SWT, would you try solving this problem in hackerrank?.keep in mind that the size of the window can be dynamic, it doesn't always have to be a fixed number like three.

If you liked this blog consider buying me a coffee😊 or support me in patreon.

check out other blogs in this series.👇

Understanding the "this" keyword as a newbie!

ProCode — Tue, 05 May 2020 10:43:10 +0000

Hey curious people👋, this is a short article about some concepts related to OOP: the this keyword, I hope this will be helpful to you.

Few days ago I posted a poll on twitter about some topics I should write next, 2 out of 5 people wanted an article on this topic, if it's helping 2 people I'll still write it!😄. If you like my articles, consider buying me a coffee so that I can continue to do this😊.

Let's Start!

`this` == 👉

it is used for referring to specific Object of a Class. We'll see what that means but before that you should know that this can be used in many ways in JavaScript, it's a bit different than this keyword in other languages. Usually in JavaScript the value of this is determined by how the function in which it is, called. Yeah I know Welcome to the weired an wonderful world of JavaScript!😅.

You'll see use of this keyword in classes, for example:

The above code is a typical example of writing a class and creating objects from it. Run this code in your IDE to see how it works. But our focus today is on the this.variables. Why are we writing the this. before every variable? Can't we write only the variables?
Well the answer is we use this. when we want some variables to be object specific, for example in the person class we have member variables like name , age , height. We want every object of the class to have their specific/individual heights, age and names. That's why we use this. before these member variables.
It simply means that these variables are used to define unique properties of unique objects/Instances of the class, and this. helps us to tell the computer that these properties belongs to "this" particular object. That's why I like to think of it as an equivalent to 👉 emoji.

`this` in general

In general, it is used to refer to the global object, (when we are not manually making it refer to something else. So in a browser it should refer to the global window object. So this == window is expected to be true. And in Node it should be equal to global.

binding `this` with objects with `call() and apply()`

If you run this code you'll observe that in the first call of returnValue() it prints the contents of the global value, but in the next two calls it will log the object specific content in the console. Remember, I told you where this will point to depends on how the function it is in, is called. There is actually a lot more you can do with this, if you wanna explore more I would suggest you take a look at the MDN docs for this. I hope you understand the basics of it by now.

Who am I?

I am a self-taught coder, Coding my life.
If you like my educational blogs Consider buying me a coffee😊 or support me in patreon so that I can continue spreading education for free.

I post random, stupid and fun analogies about coding concepts on twitter. Here's one of them about this

ProCode

@procode1

Suppose you and your friend are in your home, you want to show a feature of your home to your friend, and while doing so you refer to that feature as "this" feature. But when you both are somewhere else and you still wanna tell your friend about that feature,
1/?

13:02 PM - 06 Apr 2020

0 1

See you in the next one!

Do I really understand classes and Objects? But why should I use it?🤔

ProCode — Sun, 26 Apr 2020 17:22:46 +0000

If you like my educational blogs Consider buying me a coffee😊 or support me in patreon so that I can continue spreading education for free.

Does understanding a concept to the core gives you a really satisfactory feeling? Well get ready for some of that now. In this blog I will try to dig in and understand the idea of Classes and Objects, one of the core fundamentals Object Oriented Programming.

//   Let's Start!

Before talking about the solution uselessly, let's build up a problem first. Why do we need Class and Objects? Let's think of a problem where you and I have to build a user management system for an application, where we keep track of our users and their properties and behaviours that are allowed within our application. For example the user's name , ID and other application specific information. So what do you think we should use to keep track of our user?
To actually see the hurdles with using other methods we should use them ourselves shortly. Okay let's be real,you are only reading this so not "we", I should use them shortly, and I'm ready to be the lab-rat here.

The Problem

My Company wants me to build an user management system, where 10 to 100 user information is pulled from database and I am told to find a way to work with this data according to user's interaction with our application. The user's information includes:

User's ID

User's Name

User's Clicks Count(Updates Accordingly)

Using Arrraysto solve the problem?(Oh No!😣)

Okay! Now let's pretend I don't know what Objects and classes are and the only logical way I see to solve the problem(Provided you don't choose to manually declare 400 variables) is to use arrays. Let's see how we do that.

let userId = [1 , 2 , 3,...,100];
let userName = ["User1", "User2",.., "User100"];
//Pretty Random Click Counts
let userClicks = [6 , 23  ,..., 72];

//Function to update Click Counts
function clickCount(uName, uId)
{
  //Updating click of user at index uId
  userClicks[uId] += 1;
  console.log(uName + " Clicked " + userClicks[uId] + " times.");
}

/*
Now let's say a user clicks 
and we know userId of this
user so we call the 
function clickCount with this information.
*/
let knownId = 2;

clickCount(userName[knownId], knownId);

Phew! Did you see the problem with this? First of all, I had to create different arrays for storing user information, I am also assuming that at the same index in all the arrays the information belongs to the same user. Also there's no way to bind all the user information and function together and tell the computer this belongs to a specific user.

There could obviously be other solutions like by using Structures, enums. But we'll see how we can implement object and classes here! But before doing that first we need to be aware of what are they and how to use them and in the process, we'll write a solution for this problem.

What are classes and objects?

A class is a way to bind all the data describing an unique entity and it's associated functions together
Now what does that mean? Remember in the problem above we had some data about the user and a function along with it. A class is just a way to bind these user data and functions together and tell the computer that this belong to a specific user. These data and functions are the properties and behaviour of a particular user with in the application.

In layman's terms

Have you seen those bluePrints of houses? How many house do you think you can create from a single house plan? A lot right? A class is like a blue print. You can create Objects from it, as many as you want.so:

Class == House Plan

Object == The House

So how do we implement a class for the problem we are trying to solve? Let's see:

class user
{
    constructor (uId, uName)
    {
        this.userName   = uName;
        this.userId     = uId;
        this.userClicks = 0;
    }

    CountClicks()
    {
        this.userClicks += 1;
    }   
}

Easy , right? Now we can create as many users as we want from this user class.
The variables inside the constructor function are known as member variables/data members and the function is called member function/method, they are specific to each object. A particular user(object) is called an Instance of the class. Now how do we create object of these class? We'll see but before that are you confused about the this keyword in the code? As I only intend to talk about the idea of Objects and Classes in this blog and not much about the coding part, but you can refer to this tweet in my account, also I am planning to write a blog on the this keyword and Static methods, so stay tuned😁.

ProCode

@procode1

Suppose you and your friend are in your home, you want to show a feature of your home to your friend, and while doing so you refer to that feature as "this" feature. But when you both are somewhere else and you still wanna tell your friend about that feature,
1/?

13:02 PM - 06 Apr 2020

0 1

The Constructor function is used to initialise every object and give it, it's unique set of values. And it's necessary while writing classes. When we make a new object with the help of new keyword, the constructor function is automatically called.

Creating objects

class user
{
  constructor(uId, uName)
  {
    this.userName = uName;
    this.userId = uId;
    this.userClicks = 0;
  }

  countClicks()
  {
    this.userClicks += 1;
    console.log(this.userName + " clicked " + this.userClicks + " time.");
  }
}

//Creating Objects
let user1 = new user(1, "Tom");
let user2 = new user(2, "Jerry");
let user3 = new user(3, "ProCode");

//Using methods
user1.countClicks();
user2.countClicks();
user3.countClicks();

Smooth! Right? Always remember DRY! while coding,
DRY = Don't Repeat Yourself

So what do you think an object is?
An object is an unique entity which has it's properties and behaviours defined within the class. Ah leave it, you can make up your own definition!

Conclusion

The Class is the base structure of an object. It's like the manufacturing system in a factory, once created many similar products (object) can be created from it.

And did you realise we have already created a solution for our problem?😁
To check your understanding about the concept you can do this exercise:
Define a class car which have three member variables of your choice and two member functions speed() and break() which atleast prints "speeding" and "applying break" respectively.

Finally, it was not much of a coding tutorial, I wrote this to understand the idea of Objects and Classes more strongly.I hope you'll like it.

And if you do, please share!

Who am I?

I am a self-taught coder, Coding my life.
If you like my educational blogs Consider buying me a coffee😊 or support me in patreon so that I can continue spreading education for free.

But what is Null and Undefined?

ProCode — Sun, 19 Apr 2020 11:00:15 +0000

To answer this question we will play a game! In this game we'll ask JavaScript what it thinks about null and undefined, Does it think they are same? Or does it not? What do they exactly mean? When to use them? Ugh! Too many questions, Let's find out!

So let's bring in my friend JavaScript first!

Me : Hey JavaScript!🙋🏻‍♂️

let reply = 'Hello ProCode';

Me : We all want to know what do you think about Null and Undefined?

let reply = 'Hello ProCode';

Me : Yes! Hello, Tell us about Null and Undefined!

let reply = 'Hello ProCode';

Me : YEAH! HELLO, Can we go beyond that????

let reply = 'Hello ProCode';

🤦🏻‍♂️ JavaScript can't speak! What to do now😕? WAIT don't go anywhere! I got an idea. Even if JavaScript can not speak by itself, we can make it talk to us, By writing code! Let's see if that works.🤞

Let's think about how do we get to know what JavaScript thinks about null and undefined 🤔. Should we add null or add undefined to something to see how JavaScript interprets it? OH NO WAIT! I got another idea. We can know if JavaScript thinks null and Undefined are equal or not! Here's how👇

console.log(null == undefined);

head over to your console and try the above code and see if JavaScript thinks null and undefined are equal or not!

I am pretty sure you got a true on that one and hey! JavaScript is now talking to us. So it thinks that null is equal to undefined Hmm🤔...is it hiding anything? Well, we can find that out! How? We just have to think crazy! Remember when you think/do crazy stuff, you often break/discover something crazy. Okay, so what can we do now? Let's try adding null with a number, you might think why the hell will anyone do that? Told you, think crazy!

console.log(1 + null);
//  Output
//  1

What should be added to 1 so that we get a 1? 0 right? So does JavaScript interprets null as 0? That's our best guess for now. So now as JavaScript told us that null is equal to undefined, so adding undefined with 1 should also result to 1 right?, Or should it? Let's find out!

console.log(1 + undefined);
//  Output
//  NaN

I knew something was wrong! It was hiding something all this time. Do you feel betrayed? Actually, the fault is our's, How? We were checking for loose equality(==), but we didn't check if null and undefined were strictly equal(===) to each other. Well, let's do that now!

console.log(null === undefined);
//    Output
//    false

That was expected! Now let's just validate our previous assumption that null is interpreted as 0, so if null is interpreted as 0, what should !null(NOT null) interpret to?

console.log(1 + !null)!
//    Output
//    2

Okay, so that results in 2, which means !null is interpreted as 1 in expressions! Have we seen this kind of behaviour by any other token in JavaScript?

console.log(1 + false);
//    Output
//    1
console.log(1 + true);
//    Output
//    2

Pretty identical to what null does right? But try to not come to any conclusions quite yet, surely, we are starting to get to one, but not yet.

What does the definitions say?

Let's see what the traditional definitions of null and undefined are, and see if that makes any sense.

Null

Null literally means empty, and in terms of coding the meaning is quite the same, EMPTY! Null means the absence of anything. So if a variable contains null, that means it doesn't contain anything, which again can be interpreted as 0. Makes sense?

Undefined

Undefined literally means something which is not defined. In terms of coding if a variable is declared but nothing is assigned to it. The the variable is then undefined. So (1 + undefined) is not a valid expression so it results to NaN(Not a Number).

Let's Clear the Cloud!

Up untill now I was talking about what JavaScript thinks and what the definitions say. But now we are going to talk about how I understand this concept and be confident about it. Few days ago I posted poll in Twitter asking people to rate there understanding about the concept of null and undefined. 6 of them voted, 3 of them had chosen 0% , 2 of them had chosen 33% and only one of them had chosen 100%.

// Detect dark theme var iframe = document.getElementById('tweet-1249784435395792897-167'); if (document.body.className.includes('dark-theme')) { iframe.src = "https://platform.twitter.com/embed/Tweet.html?id=1249784435395792897&theme=dark" }

So we can observe that in this small set of 6 people too, the majority aren't really sure about their understanding of null and undefined. So the first step towards complete understanding of something should be to believe that you can understand it. I mean don't be in a fallacy but be confident.

The clear difference! (Season finale)

I use this image to remind myself about what is null and undefined. I think of null as a value that is assigned to a variable. Always Remember JavaScript never assigns null to any variable untill we do it ourselves!. Where as undefined is a state of a variable, which means that when a variable is declared but not defined/initialized with some value(not even null), that state of a variable is called undefined.Or "The variable is undefined" is what we say. And in the picture we can see that the circle never intersect each other, which means that they are in no ways equal. Now you might raise a question that JavaScript resulted/returned true when we loosely checked the equality(==)between null and undefined, so why are they different in every aspect? Well the answer is in the question itself. We loosely checked for equality, and JavaScript has it's own ways of doing that. While executing an expression it tries to type convert null and undefined to some values that it can check equality for.
Let's see how JavaScript might solve the expression null == undefined

Why `null == undefined` is considered `true` by JavaScript?

Let's say JavaScript got this expression and it has to evaluate it. First it sees that null is present in the expression, it knows that null means nothing/void so it type converts it to false type, and then in case of undefined it also type converts it to false. And it is left with false == false which is then evaluated to true. But when we check for Strict equality(===), JavaScript doesn't convert the types and so when it checks if type null is strictly equal to type undefined or not, it evaluates it as false. Remember that null and undefined can be interpreted as false type values

Use of null and undefined in mathematical expressions

If you see null and undefined in mathematical expressions, Remember this one Mantra:
"Null means nothing and is a valid value which can be interpreted as 0 in a mathematical expressions, but undefined is the state variable, a state of a variable in a mathematical expression just doesn't make sense so the expression will result to NaN(Not a Number)." Now go try out some expression using null and undefined and see what they results to.

Conclusions

Null is an assigned value
Undefined can be considered a state of a variable
Null and undefined both can be interpreted as false type values
Null can be interpreted as 0 in a mathematical expression.
Undefined in a mathematical expression doesn't make sense so it will result to NaN
I now understand null and undefined
JavaScript can not talk by itself!

Who am I?

I am a self-taught coder, Coding my life.
If you like my educational blogs Consider buying me a coffee😊 or support me in patreon so that I can continue spreading education for free.

let reply = 'Hmm...🤔That was a nice explaination'

Wait what?? JavaScript!! You can speak??

From here Genetic Algorithms looks easier🤔

ProCode — Sun, 02 Jun 2019 08:02:39 +0000

In this writing I have tried to notedown the process of writing your first basic GA’s Rather than going into the details.I have assumed that you have resources for learning it..If not stay tuned as I will be writing my next thing(whatever it is) with the details of Basic GA and its implementations.

[if you don’t know what’s GA there are some links at the bottom you might be looking for]

Sometimes people find it very hard to understand the working this algorithm from an abstract view..but believe me it can be more interesting once you Understand the concept behind it..which includes the knowing its significance , its application and etc…

Imagine a bunch of objects made by you is evolving and eventually growing a brain of themselves just infront of you..

Gave a grandpa kinda feeling , didn’t it 😂…seeing you grandchildren grow up!

=>The steps you should follow to master this algorithm!

(I assume you have done a pretty good homework about GA and know what is basically is.)
..First of all never try to mug up a single calculation in it!!!

Understand the core concepts of genetic algorithm…You can google about the DARWINIAN GENETIC ALGORITHM and clear your concepts.

1 . After its done and you feel confident about it..Its time to get the first shock..TRY TO CODE OUT WHAT YOU JUST LEARNED IN THE DARWINIAN ALGORITHM…

2 .I assume you are stuck now….(if not good job…I’m clapping 👏 go to the bottom to see some interesting videos on genetic algorithms)

3 . Here comes the saviour step now!! Leave whatever project you are on ..watch this type of videos in the provided link well for me this is the simplest you can refer to. https://youtu.be/bGz7mv2vD6g

While watching the video try to compare that with your own project. Generally you can relate easily …Do same kinda stuff he is doing in this video…

5 . Note down every step and understand the purpose..

6 . While Writing your code, you can have a tons of error working with multiple classes..One thing you should never do is doubt the framework you are using…

7 . Try and debug the whole code. the time of completion can vary from several minutes to days depending on you effort and efficiency…

8 . But always imagine the moment you are done with the code and the objects are actually evolving infrontof you!! And eventually you will get to the end point..

9 . But to have a check on yourselves if you have understand it or not.. Write some other code using Genetic algo’s with other variations you can think of..

IF YOU MADE TO THE END

CONGRATULATIONS 🎉

Happy coding😄😄

Some interesting GA videos on YouTube..

1 . https://youtu.be/FKbarpAlBkw

2 . https://youtu.be/bGz7mv2vD6g

3 . https://youtu.be/9zfeTw-uFCw

4 . https://youtu.be/VnwjxityDLQ

DEV Community: ProCode

Anonymise yourself! How to set up tor in mac? In the terminal - noob_sec series

Installation

Create template repositories from just a single JSON file! What is Dgen?

What is it?

Is it useful?

How to install it?

How to use it?

The Shape of the JSON file

Some issues with this concept

How to create Dgen in next article

How to use Qpython3 to code in python on a smartphone - UDAYANCARE CODING BOOTCAMP

Download Qpython3

How to use?

Step 1 - Open the app and click on the editor

Step 2 - Click on the second icon in the top right corner of your screen to add a file.

Step 3 - Click on Script and name the file intro.py(Actually you can name the file whatever you want, just make sure to add the extension ".py" after the name of your choice) and press OK.

Sliding Window Technique🔥

What is SWT?

Is it helpful?

How to do it?

The Problem

The brute force approach

The SWT approach

When to use it?

Understanding the "this" keyword as a newbie!

this == 👉

this in general

binding this with objects with call() and apply()

Who am I?

Do I really understand classes and Objects? But why should I use it?🤔

The Problem

Using Arrraysto solve the problem?(Oh No!😣)

What are classes and objects?

In layman's terms

Creating objects

Conclusion

Who am I?

But what is Null and Undefined?

Me : Hey JavaScript!🙋🏻‍♂️

Me : We all want to know what do you think about Null and Undefined?

Me : Yes! Hello, Tell us about Null and Undefined!

Me : YEAH! HELLO, Can we go beyond that????

What does the definitions say?

Null

Undefined

Let's Clear the Cloud!

The clear difference! (Season finale)

Why null == undefined is considered true by JavaScript?

Use of null and undefined in mathematical expressions

Conclusions

Who am I?

From here Genetic Algorithms looks easier🤔

How to create `Dgen` in next article

`this` == 👉

`this` in general

binding `this` with objects with `call() and apply()`

Why `null == undefined` is considered `true` by JavaScript?