ES6 was a major upgrade to JavaScript that made the language cleaner, safer, and more powerful for large-scale applications.
✅ 1. let and const
Block-scoped variables (fix problems with var).
let count = 1;
const PI = 3.14;
✅ 2. Arrow Functions
Shorter syntax + lexical this.
const add = (a, b) => a + b;
✅ 3. Template Literals
String interpolation and multi-line strings.
const name = "Teekam";
console.log(`Hello ${name}`);
✅ 4. Destructuring
Extract values from arrays/objects easily.
const { name, age } = user;
const [a, b] = [1, 2];
✅ 5. Default Parameters
Provide default values to functions.
function greet(name = "Guest") {
console.log(name);
}
✅ 6. Rest & Spread Operator (...)
Collect or expand values.
function sum(...nums) {}
const arr2 = [...arr1];
✅ 7. Classes
Cleaner syntax for constructor + inheritance.
class User {
constructor(name) {
this.name = name;
}
}
✅ 8. Modules (import / export)
Built-in module system.
export default function add() {}
import add from "./add";
✅ 9. Promises
Better async handling than callbacks.
fetch(url).then(res => res.json());
✅ 10. Enhanced Object Literals
Shorter object syntax.
const user = { name, age };
✅ 11. for…of Loop
Iterate over iterable values.
for (const val of arr) {
console.log(val);
}
✅ 12. Map & Set
New data structures.
const map = new Map();
const set = new Set();
✅ 13. Symbol
Unique, immutable identifiers.
const id = Symbol("id");
✅ 14. this Improvements
Arrow functions do not bind their own this.
✅ 15. Object.assign()
Clone or merge objects.
const copy = Object.assign({}, obj);
🎯 Short Interview Answer
ES6 introduced major features like
let/const, arrow functions, template literals, destructuring, rest/spread, classes, modules, promises, and new data structures like Map and Set.
These features improved readability, modularity, async handling, and scalability of JavaScript.
⭐ One-liner (Very short)
ES6 modernized JavaScript with block scoping, arrow functions, promises, classes, modules, and better syntax for writing scalable applications.
