Day 20: Learning JavaScript setTimeout(), Synchronous vs Asynchronous Code & Promises 🚀

1. setTimeout()

The setTimeout() method executes a callback function after a specified delay.

setTimeout(() => {
console.log("Hello JavaScript!");
}, 2000);

Here, the message is printed after approximately 2 seconds.

2. Synchronous JavaScript

Synchronous code executes one statement at a time, in order. Each statement normally finishes before the next one runs.

console.log("First");
console.log("Second");
console.log("Third");

Output:

First
Second
Third

3. Asynchronous JavaScript

Asynchronous operations allow JavaScript to continue running other code while waiting for certain operations to complete.

console.log("Start");

setTimeout(() => {
console.log("Inside timeout");
}, 2000);

console.log("End");

Output:

Start
End
Inside timeout

This helped me understand how JavaScript handles delayed operations.
`

4. Promise

`

A Promise is a built-in JavaScript object that represents the eventual success or failure of an asynchronous operation.

A Promise can be in one of three states:

Pending — the operation is still in progress.

Fulfilled — the operation completed successfully.

Rejected — the operation failed.
`
let myPromise = new Promise((resolve, reject) => {
resolve("Task completed!");
});

myPromise.then((result) => {
console.log(result);
});`

Output:

Task completed!

resolve() fullfills the promise and .then() handles the fullfilled result.

Today I learned the difference between synchronous and asynchronous JavaScript, how setTimeout() schedules a callback, and how Promises represent the result of an asynchronous operation.

These concepts are useful when fetching API data and working with my e-commerce website.