API Kya Hai?

API (Application Programming Interface) ek tarika hai jisse do software ek dusre se baat kar paate hain.

Socho tum ek restaurant mein ho. Tum (Client) waiter ko order dete ho. Waiter kitchen (Server) mein jaake order deta hai, khana ban'ne ke baad waapas tumhare table par le aata hai.

• Tum = Dev/Client (jo request bhejta hai)

• Waiter = API (jo request le jaata hai aur response wapas laata hai)

• Kitchen = Server (jo actually data process karta hai)

Yehi pura flow hai jo har API call mein hota hai.

The Flow: Client → Request → API → Server → Response

DEv (Client)
     |
     v
  Request
     |
     v
working with APIs
     |
     v
Server Processes
     |
     v
Response (status-code)

1. Client kuch chahta hai — data fetch karna ho, ya naya data save karna ho.

2. Wo ek Request banata hai aur API (URL) ko bhejta hai.

3. API us request ko server tak le jaata hai.

4. Server request ko process karta hai — database check karta hai, calculation karta hai, ya jo bhi zaroori ho.

5. Server ek Response wapas bhejta hai, jisme data aur ek status code hota hai jo batata hai ki request successful thi ya nahi.

Types of Requests (HTTP Methods)

Har request ka ek "type" hota hai, jo batata hai client kya karna chahta hai:

Simple yaad rakhne ka tarika — ye CRUD operations (Create, Read, Update, Delete) ka API version hai.

Status Codes — Response ka Result

Jab server response bhejta hai, uske saath ek status code aata hai jo batata hai kya hua:

• 200 → OK, sab kuch sahi gaya ✅

• 201 → Created, naya data successfully ban gaya

• 400 → Bad Request, tumne galat data bheja

• 401 → Unauthorized, login/token chahiye

• 403 → Forbidden, permission nahi hai

• 404 → Not Found, jo URL maanga wo exist nahi karta

• 500 → Internal Server Error, server side mein kuch galat hua

Yaad rakhne ki trick:

• 2xx = sab theek

• 4xx = client ne galti ki

• 5xx = server ne galti ki

Python mein APIs ke saath kaam karna (requests library)

Ab thoda code dekhte hain. Python mein requests library APIs ke saath kaam karna bohot easy bana deti hai.

import requests

# GET request - data fetch karna
response = requests.get("https://api.example.com/users")
print(response.status_code)   # e.g. 200
print(response.json())        # response body as Python dict/list

# POST request - naya data bhejna
data = {"name": "Himanshu", "age": 19}
response = requests.post("https://api.example.com/users", json=data)
print(response.status_code)   # e.g. 201 (Created)

Headers — extra info bhejna

Kabhi kabhi request ke saath authentication ya extra metadata bhejna padta hai:

headers = {"Authorization": "Bearer <token>"}
requests.get(url, headers=headers)

Query Parameters — filter/search bhejna

params = {"search": "python"}
requests.get(url, params=params)
# Final URL: https://api.example.com/users?search=python

JSON — APIs ki common language

Most APIs data ko JSON format mein bhejte/lete hain — jo basically Python ke dictionary jaisa hi structure hai (key-value pairs). Isi liye requests library mein .json() method itna handy hai.

Quick Recap

• API = do software ke beech baat-cheet karne ka tarika

• Client request bhejta hai → API server tak le jaata hai → Server process karta hai → Response wapas aata hai

• GET, POST, PUT/PATCH, DELETE — yehi 4 main request types hain

• Status code batata hai request successful thi ya nahi (2xx success, 4xx client error, 5xx server error)

• Python mein requests library se APIs use karna kaafi straightforward hai

Agli baar jab koi app data fetch karte dekho — chahe wo weather app ho ya social media feed — ab tumhe pata hai background mein exactly kya ho raha hai!

Agar ye post helpful laga, toh share karna mat bhoolna. Next post mein hum ek real API use karke ek mini-project banayenge.

If you are just getting started with javascript,DOM Manipulation is one of the first places where things start to feel real - you write code and something actually changes on the screen.

But it also has a surprising number of small traps that are not obvious until you hit them.

Here's everything I learned today , organized so you don't have to make the same mistake I did.

What is DOM ?

DOM stands for "Document Object Model" . it's basically how Javascript sees your HTML page- as a tree of elements that you can select, change,and interact with using code.

1.Selecting Elements

Before you can change anything, you need to grab the element first.

// By ID — returns a single element
document.getElementById('title')

// By class name — returns an HTMLCollection (NOT one element!)
document.getElementsByClassName('card')

// By CSS selector — cleanest option, returns first match
document.querySelector('.card')
document.querySelector('#title')

2.Changing Styles

Once you have the elements, you can change its CSS directly from JavaScript:

const title = document.getElementById('title')

title.style.backgroundColor = 'green'
title.style.padding = '15px'
title.style.borderRadius = '15px'

3.Reading Elements properties

const title = document.getElementById('title')

title.id          // returns the id value
title.className   // returns class name(s) as a string

4.Reading Content

title.textContent   // all text including hidden elements, no HTML tags
title.innerText     // only visible text (layout-aware)
title.innerHTML     // full HTML content inside the element (includes tags)

use case

• use .textContent when you just want the raw text

• use.innerText when you care about what the user actually sees

• use .innerHTML when you need to read or write HTMK tags inside an element

If you're also learning JavaScript, I hope this saves you some debugging time. These are small things but they add up fast when you're just starting out.

Let's keep building 🚀