🚀
Advanced JavaScript👉 This is where most interview questions come from
🧠 1. ES6+ Features (Modern JavaScript)🔹 Arrow Functions
const add = (a, b) => a + b;
🔹 Destructuring
const user = { name: "Sid", age: 26 };
const { name, age } = user;
🔹 Spread Operator
let arr = [1,2,3];
let newArr = [...arr, 4];
👉 Makes code clean readable
🔄 2. Array Methods (Very Important 🔥)🔹 map()
👉 Transform data
let nums = [1,2,3];
let result =
nums.map(n => n * 2);
🔹 filter()
👉 Filter data
let nums = [1,2,3,4];
let even = nums.filter(n => n % 2 === 0);
🔹 reduce()
👉 Aggregate data
let nums = [1,2,3];
let sum = nums.reduce((acc, curr) => acc + curr, 0);
🌐 3. Fetch API (Connect to Backend)fetch("
https://api.example.com/data")
.then(res => res.json())
.then(data => console.log(data));
👉 Used to get data from APIs
🔥 4. Promises (Core Concept)👉 Handle async operations
let promise = new Promise((resolve, reject) => {
resolve("Success");
});
States:
• Pending
• Resolved
• Rejected
⚡ 5. Async / Await (Modern Way)async function getData() {
let res = await fetch("url");
let data = await res.json();
console.log(data);
}
👉 Cleaner than .then()
🔁 6. Event Loop👉 JavaScript is single-threaded
• Call Stack
• Callback Queue
• Event Loop
👉 Ensures async code runs smoothly
🎯 Mini Project👉 Create:
• Fetch API data (like users)
• Display on webpage
💡 Pro Tips> Focus on:
• Promises
• Async/Await
• Fetch API
> Practice real APIs (JSONPlaceholder)
Double Tap ❤️ For More