JavaScript (ES6+) topics

🔁 1. Callbacks

• Goal: Understand how functions can be passed and executed later.

• Study Plan:

  • Write a function that takes a callback (e.g., simulate an API call).

  • Understand callback hell and how it leads to Promises.

function fetchData(callback) {
  setTimeout(() => {
    callback("Data loaded");
  }, 1000);
}
fetchData((data) => console.log(data));

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🔄 2. Promises

• Goal: Handle async operations cleanly.

• Study Plan:

  • Create basic promises using new Promise().

  • Learn .then(), .catch(), and .finally() chaining.

function fetchData() {
  return new Promise((resolve, reject) => {
    setTimeout(() => resolve("Data received"), 1000);
  });
}
fetchData().then(console.log).catch(console.error);

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⏳ 3. Async/Await

• Goal: Write cleaner async code.

• Study Plan:

  • Convert a promise-based function to async/await.

  • Handle errors using try...catch.

async function loadData() {
  try {
    const data = await fetchData();
    console.log(data);
  } catch (err) {
    console.error(err);
  }
}
loadData();

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🔧 4. Destructuring

• Goal: Unpack arrays/objects quickly.

• Study Plan:

  • Practice array/object destructuring in variables, function parameters, and return values.

const user = { name: "Alice", age: 25 };
const { name, age } = user;
console.log(name, age);

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➡️ 5. Arrow Functions

• Goal: Use concise syntax and understand lexical this.

• Study Plan:

  • Convert regular functions to arrow functions.

  • Understand how this behaves differently.

const greet = () => console.log("Hello!");

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📦 6. Modules

• Goal: Organize code into reusable files.

• Study Plan:

  • Use export/import syntax.

  • Split functions/constants across files.

// math.js
export const add = (a, b) => a + b;

// main.js
import { add } from './math.js';
console.log(add(2, 3));

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