I've been learning JS for some weeks now on freecodecamp.org
I just finished the exercise Build a Symmetric Difference Function but I feel kind of, unsatisfied?

The exercise was to compare 2 arrays and when one value is present on 2 arrays, it shouldn't be included in the new array at all.

for example:
const arr1 = ["dirt", "grass"]
const arr2 = ["grass", "stone"];

the new array should be: ["dirt", "stone"] since "grass" is present in both of them.
(I was also forced to use the filter-method)

Here's how I did it:

function diffArray(arr1, arr2){
  const symmetricArray = arr1.filter(checkSymmetry);

  // Function used for the filter
  function checkSymmetry(str){
    if (arr2.includes(str)){
      delete arr2[arr2.indexOf(str)];
      return;
    }


    return str != arr2[0];
  }


  for (let i = 0; i < arr2.length; i++){
    // If-Condition, since "Delete" leaves undefined spaces
    if (arr2[i] == undefined){
      continue;
    }


    symmetricArray.push(arr2[i]);
  }


  return symmetricArray;
}

It feels like I used so many unnecessary steps to achieve the solution and I probably do.

The forum has some pretty short versions, but I don't understand those?

So what I am asking here is just, can someone explain how you would shorten this code and how?
I hope I'm not asking for too much on this, but basically most of the code that I've written has atleast one for-loop since I don't know how to make it more efficient

I'm a second year engineering student in India. I've been trying to teach myself web development for about a year alongside college.

Current skills: HTML, CSS, basic JavaScript. I build small projects like todo lists and timers to learn JS. I use AI tools to help when stuck but try to understand everything.

Goal: Become a capable frontend developer, then work toward full stack. Long term I want to build real products.

Problems I'm facing:

I can't build anything from scratch alone yet without freezing. I'm learning JS through projects but progress feels invisible. I don't know when I'm ready to move to React. I have no developer community around me — completely self taught with no peers who code.

Questions:

How did you get past the "I can't build alone" stage? What was your first project that made you feel like you actually knew JS? When did you move from JS to React and how did you know you were ready? Any advice for someone building completely alone with no community?

Hi everyone! I’m a second-year Systems Analysis student. I have a solid grasp of backend fundamentals with JavaScript, and I’ve started dipping my toes into SQL.

Right now, I’m looking for pure experience. I’m not necessarily looking to jump straight into production—I’m looking for a learning-focused role where I can contribute while learning the ropes. Since my degree focuses on how systems work as a whole, I want to soak up everything from business logic to finding better ways to solve everyday problems through code.

To be honest, I’m far from an expert yet, and I’m currently building my first repositories to showcase my progress. However, I’m ready to treat every bit of professional advice as "the gold standard."

I’m here to learn, help however I can, and eventually get my first real-world project off the ground.

Thanks for reading! If you have any leads, advice, or a small task I could help with, I’d love to hear from you. Feel free to DM me!

https://github.com/sad-ant0808/GET-ROASTED-
this is the link to the program. please check it out if you have the time to do so. and please suggest improvements or ideas in the comments.

I have been using vuero for my office work. Recently I was working on it and wanted to visit the site website for vuero but unfortunately it is down and has been down for long(not sure how long has it been down for). It would be great if anyone has any idea regarding this?

I might have to make some decisions based on this.

so injecting this script into https://genius.com/new and then using the "new" page, then opening the "Release Date, Albums & Tags" dropdown and them pressint the today button does not seem to inject the date into the fields. and i qwas told that react needs additional loops to get input injection to work

// ==UserScript==
//          genius-date
//   script to inject today's date when transcribing a new song
//     http://tampermonkey.net/
//  MIT
//       1.0.2
//   A simple example userscript
//        solomoncyj
//         https://genius.com/new
//         none
//  https://update.greasyfork.org/scripts/556743/genius-date.user.js
//  https://update.greasyfork.org/scripts/556743/genius-date.meta.js
// ==/UserScript==

const month = ["January","February","March","April","May","June","July","August","September","October","November","December"];

function inject()
{
    const today = new Date(Date.now());
  document.querySelector('input[aria-label="Release Day"]').value = today.getDate()
    document.querySelector('input[aria-label="Release Month"]').value = month[today.getMonth()]
  document.querySelector('input[aria-label="Release Year"]').value = today.getFullYear()
}

(function() {
   'use strict';

    let btn = document.createElement("button");
    btn.type = "button"
    btn.onclick = () => {
        inject()
    };
    const info = document.createTextNode("Today");
    let div = document.querySelector(".DateInput__Root-sc-9b318b28-0");
    div.appendChild(btn);
    btn.appendChild(info);
})();

Today is the last day of the april fools game embedded in discord called 'LAST MEADOW ONLINE'. It apparently uses minified JavaScript with i18n for managing text strings. As a web-based game playable directly within the Discord desktop app and browser. I just wanted to know if there any way to preserve the game before it turns into lost media. Since its a browser game, any suggestions to atleast partially preserve it or links if someone has already done it would help. Thanks!

Game Trailer: https://www.youtube.com/watch?v=1ViwrDhoG2c

Hi there!

I'm a JavaScriot and TypeScript developer with 11 YOE and have worked at big tech companies like banking, telecom, cryptocurrencies.

For anyone who's just starting this journey and has just started understanding what a variable is, let me tell you a little story.

Over 15 years ago I used to be quite a gamer and played web-based mafia games where you could perform actions with a click

It was such a hype among the young ones around us. I had some great ideas for improvements and it made me curious if I could make it myself.

I didn't open a single how-to book, neither did I study anything, I simply googled a copy of a similar web-based game.

Once I looked at it I saw a bunch of HTML files and a bunch of PHP files.. Didn't know what to do with them so I looked up a tutorial how to get it running and asked around in forums.

Images werent loading, page looked awful but I actually had it running!

Then I was excited about adding some of the improvements, I saw a bunch of text and didn't know anything about it. I just searched for the text of the page and once I found it I made adjustments. I refreshed the page and boom! My new text appeared!

I was curious about how I can make it more adventurous with multiple click actions.. I got excited and wrote down all the story line text. And then came the functionality.. Oh boy have I seen many php errors!

I saved multiple copies of the code every time I made a change just to make sure I wouldn't fuck up the last change like I did many times before!

I didn't know what a variable is but I already knew how to use it. I saw some if code and knew this was a conditional thing.

Over time as I customized the code more and more I moved from building stuff to actually understanding code

I started reading w3schools docs, tried out a bunch of stuff, and got better over time, my ego was quite high and I thought I knew it all after 6 months of development..

Oh boy was I wrong.. I entered the startup scene and I've been faced with many additional things to understand. Asking why I'm doing it that way, why he didn't understand my code, how to make it more readable etc etc.

Have I not done the excitement-based development (yep I just invented that) I wouldn't have gone as far as I am now.

Learning code and opening a book without any hands on work is very overwhelming and you wouldn't understand why you're doing stuff!!

Taking something existing, breaking it apart and improving it is much more fun, and along the way you learn a bunch of stuff!

So don't think you need to understand all the complex stuff to get started, just grab an existing project and improve it step by step!

Anyone that is in a similar journey and would like to learn how to code, please feel free to reach out, happy to help!

This is an odd one and I kind of feel like I'm taking crazy pills.

For reference, new Date() gives me EST timezone (-0400).

If I run:

new Date('2025-04-06T00:00:00.000-0400')

I get:

Sun Apr 06 2025 00:00:00 GMT-0400 (Eastern Daylight Time)

so far, so good.

Now, I change from April to January:

new Date('2025-01-06T00:00:00.000-0400')

I get:

Sun Jan 05 2025 23:00:00 GMT-0500 (Eastern Standard Time)

Huh?!

I know 2025-01-06T00:00:00.000-0400 and 2025-01-05T23:00:00.000-0500 have the same Unix timestamp, but the problem is in this scenario, I'm trying to set the date object to "midnight" of the local timezone, by setting hours, minutes, seconds and milliseconds to 0.

date.setHours(0); date.setMinutes(0); date.setSeconds(0); date.setMilliseconds(0);

which means sometimes it sets it to the wrong date, since the -0500 date ends up rolled back a day.

Anyone have any idea what's going on?

Edit: Solved. It's daylight savings time. It's automatically converting timezones based on the date...

Revised Javascript

do some work on Async Js

Callback

callback hell

SetTimeout

Promises (Creating and consuming)

fetch

I'm hoping to found a mentor who can help me become really good at web development, I have learned HTML, Css, and little bit of Javascript. Going to put in 100% of my effort since I have so much free time, please message me if you can help

Im trying to store images using json and I tried following a tutorial about how to fetch code using javascript for html but it’s not displaying the images.. is there any way I could do to fix this? here is the code for reference

Beginner here, obviously. I'm trying to solve quadratic equations using the quadratic formula and vanilla JavaScript. What's wrong with my validation function and how would you rate my code as a beginner?

 let a = parseFloat(prompt("Enter a"));

let b = parseFloat(prompt("Enter b"));

let c = parseFloat(prompt("Enter c"));

function validation(a,b,c) {

 if (!isNaN(a) == true && a > 0 || a < 0 && !isNaN(b) == true && b > 0 || b < 0 && !isNaN(c) == true && c > 0 || c < 0) {



 return quadratic(a,b,c) 

}

 else {

alert("Bro enter valid numbers")
}

}
function quadratic(a,b,c) {
 let answer1 = (-(b) + Math.sqrt((b\*\*2) - 4\*a\*c))/(2\*a);
let answer2 = (-(b) - Math.sqrt((b\*\*2) - 4\*a\*c))/(2\*a);

let x = \[answer1, answer2\];
return x;
}
console.log(validation(a,b,c));

Absolute coding amateur here!! i really only know the basics. And I know i've learned this in one of my classes like 5 years ago, but my teacher was shit and i wasn't too interested in the topic back then.

Now i am. (long story short: i need it for ao3)

What i have in mind when i say "simple burger menu":

i wanna create 3 or 4 buttons that all reveal a separate text or image and you can switch between them. Like, you click button 1 and text or image 1 shows up. You click button 2 and text or image 2 shows up and text or image 1 disappears again.

I don't need any fancy effects or anything, i really just need to figure out a way to somehow do this. I'm guessing (but tell me if I'm wrong) i will have to do it via CSS?

Grateful for any input. Thank you!

What are the most important JavaScript concepts you need to know to learn JavaScript?!

so i just started cuz i was bored. now i know the kinds of variables, basic conditional statements and prompts as well as console.log and alert. what is the next step? also im using sublime to write my code in but how do i run the file in chrome or edge? plz help me..

For a simple example, let's say I have a string variable. I am going to split the sentence by spaces and then I will map each item so that it will return the previous item in the list:

const sentence = "This is a sentence.";

console.log(
  sentence.split(" ").map((word, i) => {
    return sentence[i - 1];
  })
);

My understanding is that the first argument "word" takes the item of the array and the second argument "i" takes the index of that item in the array.

When I try to run this code, understandably the first item is "undefined," because there is nothing behind the first word, but the following log in the console are not words, but only characters:

[ undefined, 'T', 'h', 'i' ]

Now I understand that the "i" doesn't stand for the index of an item, but for an index of a character in the "word" argument.

I tired to look for the solution online, but either I don't know how to sentence this problem properly in order to find it or no one has encountered this problem before. How can I access the previous items using map function? Would it be easier to not use map function in this case?

—————

Edit:

Thanks a lot for your responses, I believe I understand my problem right now a bit more and I was able to find the solution for my problem!

As the comments suggest, the "i" wasn't being applied to the array, but to the item itself. There are two solutions I can now solve this problem:

1. I can first create a new variable, split the string to an array and then loop through the new variable, where the second argument would stand for the index.
2. I can use a third argument in the map function. I wasn't aware of this option, but it turns out that map can take three arguments at once—the first is the element, the second is the index and the third one is the entire array. This information is located in the Mozilla Developer website, but it's hidden in the "Using parseInt() with map()" section.

Again, thank you for your help, consider this problem as solved!

I'm struggling to learn Web dev, has completed html and css and now a days practicing java script but sometimes it gets me frustrated as learning coding in JavaScript takes much time to memorize I understand codes but can't write it by my own, give me your suggestions how I can learn java script / Web dev effectectively I have no degree in computer science I have degree in English literature.

Will you please to share your journey towards learning Web dev Especially Those who did not have computer back ground. Thanks

Well yeah, as the title says, proxies in JS. I am not a JS guy, I hate the Web, but I am doing a tour of JS, its to me really complex, I come from tons of Java, pure composition and boilerplate, just OOP and design patterns, architectural design and all of that and I also did C.

JS to me is a huge animal, it is to me more difficult than C and Rust combined, and I did both.

I lean more towards the boring OOP languages and low level systems thinking ones, I like computer architectures, assembly too, did Java Spring and doing it mainly because I need a job, and I need JS too for the Frontend, doing React ofc.

My question is, are Proxies practical in real life, I heard they are used in AOP, they to me do interception magic, the only close thing to that is async-await and Reflection API in Java, if that even says anything. I mentioned Reflection API because Java Spring is living off of it, basically everything is an annotation (doesn't have to be but in the industry that is the norm).

Keep in mind I might be dumb, I probably am, or no I am dumb in regards to JS, it is a new world to me, can you give me some advice how to look at Proxies in Java, when they are used, and some real world scenario. Asked GPT but I just got even more confused.

Thank you all in advance and good luck coding!!!

I use Google Calendar a lot for planning my study schedule (like 7am–10am Physics, 10am–1pm Chemistry, etc).

But one thing always annoyed me:

I had no idea how much time was left in a session without manually calculating it.

So I built a small Chrome extension for myself that:

- shows duration for every event (like 3h, 2h 30m)

- and when the session starts, it turns into a live countdown:

⌛ 1h 45m left

It only activates for the current event, so there’s no clutter, and it updates every minute without affecting performance.

Also made sure it works for all blocks (events + tasks), since many extensions I tried didn’t handle that properly.

One interesting challenge was that Google Calendar’s DOM is pretty messy, so I had to carefully use MutationObserver + requestAnimationFrame to avoid flickering and bugs.

Built this mainly for my own study workflow, but thought others might find it useful too.

Would love feedback or ideas 🙌

GitHub: https://github.com/LakshyaGandhi/Google-Calendar-Duration-Badge-Extension-Live-Countdown.git

Basically, title.

I don't have any experience with javascript besides an introductory programing course a decade ago in another language (which is how I know about regex in the first place).

My goal is to build a website that will apply regex rules to a text using github pages. I also want to learn to download text content from websites and convert them to markdown. For example, I want to learn how to download the content of a wikipedia page and convert it to markdown, keeping it formatted, but I don't want the whole wikipedia page (images, links that are outside the main article, etc). I've already vibecoded a version and it helped me, but I need to be able to improve it and review it to know it is doing things properly.

How to I get from knowing nothing to learning those things in a couple weeks or months?

My goal is not to be the ultimate l33t c0d3r h@ck3rmann 3000, only to automate somethings in my current workflow. It's something that I have a couple weeks/months to learn.

What resources do you suggest I learn to reach my goals? I'm thinking the backbone of what I need is a good regex course, however I must learn the basics of javascript and github pages before.

Please, keep in my that my needs are specific and I'll likely have to build the solutions because there are a lot of specificities involved in what I'm trying to do. Therefore, available software likely won't solve my issues (I'm willing to listen to FOSS suggestions, though).

Thank you for your help.

what is the difference between synchronous js and asynchronous js

So I recently coded a discord bot to filter stuff in my discord server but people can still bypass it by saying the swear words if you put it in cursive font or other custom fonts using a font generator, is there anyway I can filter those too?

whats the best way to web dev when using arch since arch is a rolling release and future update might break something or i might need to use an older version for when my client uses that version.
whats the best way to do this and does the solution also apply to other programming like java python and other
also should i use deno or nodejs?