JavaScript Basics: Interactive Web Pages with JavaScript

Stop writing JavaScript for every single form validation. HTML already does most of it - better, faster, and more reliably. Many apps still do this: // JavaScript validation logic if (!email.includes('@')) { showError('Invalid email'); } Here’s what you could do instead: <input type='email' required> That’s it. Modern browsers already provide: • Format validation • Required field checks • Built-in error messages • Keyboard and autofill optimisations • Screen-reader-friendly errors • Mobile-friendly input modes All without a single line of JavaScript. Native HTML validation wins for many reasons: → Works even if JavaScript fails or hasn’t loaded yet → Browser-optimised and faster than custom JS → Accessible by default (with real semantics and announcements) → Mobile keyboards adapt automatically (email, URL, number, etc.) → Maintained by browser vendors, not by you And you get it just by using the right attributes: ✅ required ✅ minlength / maxlength ✅ min / max ✅ pattern ✅ type='email' ✅ type='url' ✅ type='number' This is called progressive enhancement: → Start with what the browser guarantees. → Add JavaScript only when you need something more. Of course, there are trade-offs. Use JavaScript when you actually need: • Custom error messages • Cross-field validation • Business rules (e.g., 'password cannot match username') • Server-driven constraints But don’t replace what the platform already provides for free. Before writing another line of JavaScript, ask yourself: does HTML already do this? #WebDevelopment #Frontend #HTML #JavaScript #WebDev

Tagged Template Literals (The Magic Function Call) in JavaScript 🚀 𝐓𝐡𝐞 𝐌𝐚𝐠𝐢𝐜 𝐨𝐟 "𝐓𝐚𝐠𝐠𝐞𝐝 𝐓𝐞𝐦𝐩𝐥𝐚𝐭𝐞𝐬": 𝐂𝐚𝐥𝐥𝐢𝐧𝐠 𝐅𝐮𝐧𝐜𝐭𝐢𝐨𝐧𝐬 𝐖𝐢𝐭𝐡𝐨𝐮𝐭 () 🪄 𝐇𝐞𝐚𝐝𝐥𝐢𝐧𝐞: 𝐄𝐯𝐞𝐫 𝐰𝐨𝐧𝐝𝐞𝐫𝐞𝐝 𝐡𝐨𝐰 𝐬𝐭𝐲𝐥𝐞𝐝.𝐝𝐢𝐯 𝐨𝐫 𝐠𝐪𝐥 𝐰𝐨𝐫𝐤𝐬? 𝐈𝐭'𝐬 𝐧𝐨𝐭 𝐦𝐚𝐠𝐢𝐜, 𝐢𝐭'𝐬 𝐣𝐮𝐬𝐭 "𝐓𝐚𝐠𝐠𝐞𝐝 𝐓𝐞𝐦𝐩𝐥𝐚𝐭𝐞𝐬" 🧠 Hey LinkedInFamily, We all love Template Literals (backticks) for mixing variables with strings. 𝐜𝐨𝐧𝐬𝐭 𝐦𝐬𝐠 = "𝐇𝐞𝐥𝐥𝐨 ${𝐧𝐚𝐦𝐞}"; But did you know you can put a Function Name right before the backticks? This is called a 𝐓𝐚𝐠𝐠𝐞𝐝 𝐓𝐞𝐦𝐩𝐥𝐚𝐭𝐞, and it completely changes how the string is processed. 🔍 How does it work? When you use a tag (function) before a template string, the browser doesn't just return a string. Instead, it calls the function and passes: 1. An array of the plain text parts. 2. The values of all variables (${...}) as separate arguments. This gives you full control to modify, sanitize, or reformat the data before it becomes a final string. 💡 Real-World Power: This is exactly how libraries like Styled Components working! 1. They take your CSS string. 2. They process it inside the tag function. 3. They generate a unique class name and inject the styles. 🛡 My Engineering Takeaway JavaScript allows us to create our own "mini-languages" (DSLs) using this feature. It’s a powerful tool for libraries that need to parse custom structures like CSS, HTML, or SQL queries safely. 𝐒𝐭𝐨𝐩 𝐣𝐮𝐬𝐭 𝐜𝐨𝐧𝐜𝐚𝐭𝐞𝐧𝐚𝐭𝐢𝐧𝐠 𝐬𝐭𝐫𝐢𝐧𝐠𝐬. 𝐒𝐭𝐚𝐫𝐭 𝐩𝐫𝐨𝐜𝐞𝐬𝐬𝐢𝐧𝐠 𝐭𝐡𝐞𝐦 🛠️✨ Ujjwal Kumar || Software Developer || JS Architecture Enthusiast || Metaprogramming #JavaScript #WebDevelopment #TaggedTemplates #ES6 #UjjwalKumar #TheDeveloper #SoftwareEngineering #CodingTips #StyledComponents #AdvancedJS

So, JavaScript is kinda like the backbone of modern web development. It's crazy to think about how far it's come since 1995. That's a long time. And now, parsing and interpreting its code is a crucial part of the process. You gotta know how to break it down, right? I mean, take Abstract Syntax Trees (ASTs) for example - they're like a map of the code's structure. And they're used everywhere, from code analysis tools to integrated development environments (IDEs). Libraries like acorn, esprima, and babel-parser make it possible to parse JavaScript code into ASTs, which is pretty cool. It's powerful. But, let's get into the nitty-gritty - when you're parsing JavaScript code, you're essentially interpreting its structure through these ASTs. And that's where things can get interesting. You can use the Babel parser to parse JavaScript code and generate an AST, like this: ```javascript const parser = require("@babel/parser"); const code = `const add = (a, b) => a + b;`; const ast = parser.parse(code); ``` And then, you can traverse and manipulate these ASTs using libraries like rebabel or estraverse. It's like navigating a tree, where each branch represents a different part of the code. It's complex. Now, when it comes to parsing JavaScript, there are some edge cases to consider - like strict mode and prohibited syntax. And, you can use source maps to map transformed code back to the original source, which is super useful. It's a game-changer. Companies like Facebook and Airbnb are already using AST manipulation for code analysis, transpilation, and bundle optimization. And, to optimize parsing performance, it's all about avoiding unnecessary traversals, leveraging caching, and using parallel processing. It's a strategy. So, if you're looking to take your JavaScript skills to the next level, you gotta understand the power of parsing and interpreting its code. It's all about innovation, creativity, and strategy. Check it out: https://lnkd.in/gJm8smSs #JavaScript #WebDevelopment #CodeOptimization

Angular 57 out of 100 interview questions: Q57: What is the difference between let and var keyword? Difference Between let and var in JavaScript 🚀 Both let and var are used to declare variables in JavaScript, but they have key differences in scope, hoisting, and re-declaration. Feature var 🟡 let 🔵 Scope Function-scoped (accessible inside the entire function) Block-scoped (only accessible within {} block) Hoisting Hoisted and initialized with undefined Hoisted but not initialized (can't be used before declaration) Re-declaration Allowed in the same scope ❌ Not allowed in the same scope Global Object Property Declared in global scope, adds a property to window object (in browsers) Does not add to window object Use Case Used in older JavaScript versions, avoid in modern code Recommended for modern JS development Code Example: function test() { if (true) { var x = 10; // Function-scoped let y = 20; // Block-scoped } console.log(x); // ✅ Accessible console.log(y); // ❌ ReferenceError (y is block-scoped) } test(); Key Takeaways: Use let instead of var to avoid unexpected issues due to hoisting and scope leakage. let is more predictable and prevents accidental variable overwrites.

𝗧𝗵𝗲 𝗣𝗼𝘄𝗲𝗿 𝗼𝗳 𝗝𝗮𝘃𝗮𝗦𝗰𝗿𝗶𝗽𝘁 You want to add JavaScript to your website. But where do you start? JavaScript makes the web interactive. It powers modern user experiences. You use JavaScript on the frontend for UI, animations, and events. You use it on the backend for servers, APIs, and databases. There are three core ways to include JavaScript: inline, internal, and external. - Inline JavaScript is written directly inside HTML elements. It is good for small demos and quick testing. - Internal JavaScript lives inside a script tag in the same HTML file. It is good for small websites and single-page demos. - External JavaScript is the most professional and scalable way. You write JavaScript in a separate file and link it to your HTML. External JavaScript is clean, maintainable, and reusable. It loads faster with caching and is the industry standard. Frontend JavaScript runs in the browser and focuses on user interactions and API calls. Backend JavaScript runs on the server using Node.js. Popular libraries and frameworks include React.js, Vue.js, and Angular. Understanding scope helps you avoid bugs and confusion. JavaScript has a massive community with millions of developers worldwide. You can find endless tutorials, blogs, and open-source projects. If you are just starting, try internal JavaScript. As your project grows, move to external JavaScript. Source: https://lnkd.in/ggKWZFje

Stop writing JavaScript to open a modal. HTML can now do it alone. Here is how web interactions are changing. 1. The old way We usually write code for simple tasks. To open a pop-up. To show a dialog. It requires event listeners. It requires logic. 2. The new solution Meet the Invoker Commands API. It allows buttons to control elements directly. You do not need JavaScript files. You only use HTML. 3. How it works You add two attributes to a button: - commandfor: The ID of the element you want to control. - command: The action you want to perform. 4. The actions The browser knows what to do based on the command: - show-modal: Opens a dialog. - close: Closes a dialog or a popover. - toggle-popover: Shows or hides a popover. - open / close: Controls a details element. 5. The code Instead of a script, you simply write: <button commandfor=my-dialog command=show-modal>Open</button> It is clean. It is easy to read. 6. Custom Commands Need more logic? You can define your own actions starting with `--`. Example: `command="--spin-image"` You keep the HTML declarative. You just handle the specific logic in JS. 7. The benefits - Less code: No need to write JS functions. - Native: The browser handles the logic. - Accessible: Better support for screen readers. Global compatibility is at 70.21%. Safari needs a specific flag to work. The flag is: InvokerAttributesEnabled. It simplifies the web. I prepared a live demo and gathered some good articles. Send me a DM to get the links. Are you ready to delete your scripts?

🔹Asynchronous JavaScript — Callbacks, Promises & Async/Await JavaScript doesn’t wait. It executes code asynchronously, which makes web apps fast and responsive. Understanding async JS is mandatory for APIs, React, and backend communication. 1️⃣ What is Asynchronous JavaScript? Async code allows tasks like: ✔ API calls ✔ Database requests ✔ Timers to run without blocking the main thread. 2️⃣ Callbacks (The Old Way) A function passed into another function to run later. setTimeout(() => { console.log("Data loaded"); }, 1000); ❌ Hard to manage ❌ Leads to callback hell 3️⃣ Promises (Cleaner Approach) fetch(url) .then(res => res.json()) .then(data => console.log(data)) .catch(err => console.error(err)); ✔ Better readability ✔ Handles success & failure 4️⃣ Async / Await (Best Practice) async function getData() { try { const res = await fetch(url); const data = await res.json(); console.log(data); } catch (err) { console.error(err); } } ✔ Looks synchronous ✔ Easy to debug ✔ Widely used in production 5️⃣ Why This Matters ✔ Fetch backend data ✔ Handle user actions smoothly ✔ Required for React & Spring Boot APIs Async JavaScript = professional frontend code. #AsyncJavaScript #Promises #AsyncAwait #FrontendDevelopment #JavaFullStack #WebDevJourney #CodingLife #PlacementReady

🚀 JavaScript – Bringing Websites to Life So far, we’ve learned HTML for structure and CSS for design. Now it’s time to move to the most powerful part of frontend development — JavaScript. JavaScript is what makes websites interactive, dynamic, and intelligent. 🔹 What is JavaScript? JavaScript is a programming language used to: Add interactivity Handle user actions Update content dynamically Control logic in web applications Without JavaScript, websites are mostly static. 🔹 Why JavaScript is Important JavaScript allows websites to: Respond to clicks 🖱️ Validate forms 📝 Show/hide content Fetch data from servers Build complete web applications 👉 Almost every modern website uses JavaScript. 🔹 Where JavaScript Runs JavaScript can run in: Browsers (Chrome, Firefox, Edge) Servers (using Node.js) This makes JavaScript useful for both: Frontend development Backend development 🔹 How JavaScript Works with HTML & CSS Think of a website like a human body: HTML → Skeleton (structure) CSS → Skin & appearance JavaScript → Brain (logic & actions) All three together create a complete web experience. 🔹 How to Add JavaScript to a Webpage Inline JavaScript <button onclick="alert('Hello!')">Click me</button> Internal JavaScript <script> alert("Hello World"); </script> External JavaScript (Recommended) <script src="script.js"></script> 👉 External JavaScript keeps code clean and scalable. 🔹 First JavaScript Example console.log("Hello, JavaScript!"); This prints output in the browser console and is often used for debugging. 🧠 Beginner Tip Don’t rush JavaScript. Focus on understanding logic, not memorizing syntax. JavaScript becomes easy when you practice step by step. ✅ Key Takeaway JavaScript is the bridge between design and functionality. Learning it opens the door to: React Backend development Full-stack applications 🚀 Next up: variables, data types, and how JavaScript stores information . . #JavaScript #WebDevelopment #Frontend #LearningInPublic #FullStackJourney #BeginnerFriendly

JavaScript just got a whole lot more interesting. DOM - it's like the bridge between HTML, CSS, and JavaScript. Without it, JavaScript would be pretty useless. So, what is DOM? It's the Document Object Model, a programming interface that turns your HTML page into a tree of objects - think of it like a big family tree, but instead of people, it's got HTML elements and CSS styles. This tree structure is what lets JavaScript read, add, or delete stuff dynamically. It's like having a superpower. DOM connects the dots between HTML, CSS, and JavaScript, making it possible for JavaScript to control the webpage. It's the standard object model and programming interface for HTML, defining how you interact with your HTML page - pretty important stuff. You should care about DOM because it lets you do some cool things: change HTML elements, attributes, and CSS styles on the fly. It's like being a web page architect - you can remove existing elements and attributes, add new ones, react to what's already there, and even create new events. All this power, and it's pretty accessible too. You can get to DOM elements in a few ways: - getElementById is like finding a specific person in a crowd - it returns one element. - getElementsByClassName is more like finding all the people wearing the same shirt - it returns a bunch of elements with the same class. - getElementsByTagName is similar, but it's like finding all the people with the same job title - it returns elements with the same tag. - querySelector is like finding the first person who fits a certain description - it returns the first matching element. - querySelectorAll is like finding all the people who fit that description - it returns all the matching elements. Check out this link for more info: https://lnkd.in/g8KZyW4q #JavaScript #DOM #WebDevelopment