A–Z Web Development Lexicon & Glossary (Hinglish)
Web development ke A se lekar Z tak ke important concepts ka technical dictionary, jisme definitions, syntax, code examples aur common uses shamil hain.
[A]
Array
- Definition: JavaScript mein values ka ek ordered, zero-indexed collection jo multiple data types ko hold kar sakta hai.
- Syntax:
const arr = [item1, item2, item3]; - Example:
const tech = ['HTML', 'CSS', 'JavaScript']; console.log(tech[0]); // 'HTML' - Common Use: Products ki list, user profiles aur menu items store karna.
- Related Concepts:
Array.map(),Array.filter(),Array.reduce().
async / await
- Definition: Promises ke upar bana modern syntactic sugar jo asynchronous code ko synchronous jaisa readable banata hai.
- Syntax:
async function getData() { const res = await fetch(url); return await res.json(); } - Common Use: Server se data fetch karna, background API calls handle karna.
- Related Concepts:
Promise, Event Loop,try...catch.
Attribute
- Definition: HTML opening tag ke andar likhe jaane wale special keywords jo element ko extra configuration ya metadata provide karte hain.
- Syntax:
<tag attribute="value"> - Example:
<input type="email" required placeholder="naam@example.com"> - Related Concepts: DOM Properties,
dataset,setAttribute().
[B]
Box Model
- Definition: CSS ka foundational model jisme har element ek rectangular box hota hai jisme Content, Padding, Border aur Margin hote hain.
- Syntax:
box-sizing: border-box; - Common Use: Element ki width/height calculate karna aur horizontal scrollbar se bachna.
- Related Concepts: Margin Collapsing,
border-box,content-box.
Boolean
- Definition: Ek primitive data type jiski sirf do values ho sakti hain:
trueyafalse. - Example:
const isLoggedIn = user.token !== null; - Related Concepts: Truthy / Falsy values, Strict Equality
===.
[C]
Closure
- Definition: Jab koi inner function apne bahar wale parent function ke variables ko hamesha yaad rakhta hai, chahe parent function execute hokar return kyun na ho chuka ho.
- Example:javascript
function createCounter() { let count = 0; return () => ++count; } const counter = createCounter(); console.log(counter()); // 1 - Common Use: Private state maintain karna aur data encapsulation.
- Related Concepts: Lexical Scope, Scope Chain.
CSS Cascade Layers (@layer)
- Definition: CSS ka feature jisse aap stylesheets ke priority order ko explicitly declare kar sakte hain bina selector specificity ke jhanjhat ke.
- Syntax:
@layer reset, base, components, utilities; - Common Use:
!importantescalation wars ko permanently khatam karna. - Related Concepts: Specificity, The Cascade.
[D]
DOM (Document Object Model)
- Definition: Browser ki memory mein bana HTML page ka object tree, jise JavaScript se dynamically modify kiya ja sakta hai.
- Syntax:
document.querySelector('.card') - Common Use: Button click par content change karna, dynamic elements render karna.
- Related Concepts: Event Listeners, Critical Rendering Path.
DOCTYPE
- Definition: HTML document ki sabse pehli line jo browser ko Standards Mode mein render karne ke liye instruct karti hai.
- Syntax:
<!DOCTYPE html> - Related Concepts: Quirks Mode, Standards Mode.
[E]
Event Loop
- Definition: JavaScript runtime ka wo engine jo Call Stack, Microtask Queue (Promises) aur Macrotask Queue (
setTimeout) ke execution sequence ko coordinate karta hai. - Related Concepts: Call Stack, Microtasks, Macrotasks.
Event Delegation
- Definition: Ek parent element par single listener lagakar sabhi child elements ke clicks ko Event Bubbling ke through handle karne ka pattern.
- Related Concepts: Event Bubbling,
event.target.
[F]
Flexbox
- Definition: CSS ka 1D layout model jo rows ya columns mein items ke beech space distribute karta hai.
- Syntax:
display: flex; justify-content: center; align-items: center; - Related Concepts: Main Axis, Cross Axis, CSS Grid.
[G]
Grid (CSS Grid)
- Definition: CSS ka 2D layout model jo simultaneously rows aur columns dono ko control karta hai.
- Syntax:
display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); - Related Concepts: Flexbox,
frunit,auto-fit.
[P]
Promise
- Definition: Asynchronous task ke future result (success ya failure) ko represent karne wala object.
- States:
pending,fulfilled,rejected. - Related Concepts:
async/await,.then(),.catch().
[Z]
z-index
- Definition: Positioned element ka 3D stacking order (screen ke upar kaun dikhega) set karne wali CSS property.
- Syntax:
z-index: 10; - Related Concepts: Stacking Context,
isolation: isolate.