JS Code Collection

Pratham-Parikh — Fri, 06 Mar 2026 15:25:32 +0000

I Organized 70+ JavaScript Programs From Beginner to Advanced (With Examples)

When I started learning JavaScript, I realized something frustrating.

Most tutorials explain concepts, but they don't give enough practice programs.

You read about loops, arrays, or functions — but you rarely get a structured collection of programs to actually practice them.

So I decided to solve that problem.

I created a collection of JavaScript programs organized from beginner to advanced. Each program includes comments explaining what the code is doing so beginners can understand it easily.

Below are a few examples from the collection.

1. Reverse a String

function reverseString(str) {
    return str.split("").reverse().join("");
}

console.log(reverseString("javascript"));

What this teaches:

String methods
Arrays
Method chaining

2. Remove Duplicates From an Array

const arr = [1,2,2,3,4,4,5];

const unique = [...new Set(arr)];

console.log(unique);

Concepts used:

ES6 Set
Spread operator

3. Check if a Number is Prime

function isPrime(num){
    if(num <= 1) return false;

    for(let i = 2; i < num; i++){
        if(num % i === 0){
            return false;
        }
    }

    return true;
}

console.log(isPrime(7));

Concepts used:

Loops
Conditionals
Mathematical logic

Why Practice Programs Matter

Reading theory is not enough.

To actually improve your JavaScript skills you need to:

Write small programs
Solve logic problems
Understand how concepts combine in real code

This is why many developers struggle in interviews — they know concepts but lack practice solving problems with code.

What the Full Collection Includes

The full collection contains 100+ JavaScript programs, including:

Basic logic programs
Array problems
String manipulation
Number algorithms
Beginner interview questions
Intermediate logic challenges
8+ Mini Projects

All programs are organized from beginner to advanced, making it easier to practice step by step.

If You Want the Full Collection

I have organized all the programs in a clean folder with well-commented code.

👉 Complete JS Code Collection

If you're learning JavaScript, I hope this helps you practice more and improve faster.

Also feel free to comment your favorite JavaScript practice problems below!

DEV Community: Pratham-Parikh