JavaScript Program to Check Magic Number

Posted in JavaScript Tutorial

Updated on Jan 11, 2024

By Mari Selvan

👁️ 99 - Views

⏳ 4 mins

💬 1 Comment

JavaScript Program to Check Magic Number

Photo Credit to CodeToFun

🙋 Introduction

In the world of programming, the concept of magic numbers is a fascinating one.

A magic number is a number in which the eventual sum of its digits, when the sum is recursively calculated, leads to a single-digit number that is 1. If the final sum is not 1, the number is not considered magic.

In this tutorial, we'll delve into a JavaScript program that checks whether a given number is a magic number or not.

📄 Example

Let's examine the JavaScript code that performs the magic number check.

isMagicNumber.js

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// Function to check if a number is magic
function isMagicNumber(num) {
  while (num > 9) {
    let sum = 0;

    // Calculate the sum of digits
    while (num > 0) {
      sum += num % 10;
      num = Math.floor(num / 10);
    }

    num = sum;
  }

  // Check if the final sum is 1
  return num === 1;
}

// Driver program
// Replace this value with your desired number
const number = 19;

// Check if the number is magic
if (isMagicNumber(number)) {
  console.log(`${number} is a Magic Number.`);
} else {
  console.log(`${number} is not a Magic Number.`);
}

💻 Testing the Program

To test the program with different numbers, simply replace the value of number in the code.

Output

19 is a Magic Number.

Run the script to see whether the number is a magic number or not.

🧠 How the Program Works

The program defines a function isMagicNumber that takes an integer as input and checks if it is a magic number.
Inside the function, it iteratively calculates the sum of the digits of the number until the number becomes a single-digit number.
It then checks if the final sum is equal to 1, indicating a magic number.

📏 Between the Given Range

Let's take a look at the javascript code that checks for Magic Numbers within the specified range.

findMagicNumbersInRange.js

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// Function to check if a number is a magic number
function isMagicNumber(num) {
  while (num > 9) {
    let sum = 0;
    while (num > 0) {
      sum += num % 10;
      num = Math.floor(num / 10);
    }
    num = sum;
  }
  return num === 1;
}

// Driver program to find magic numbers in the range 1 to 50
function findMagicNumbersInRange(start, end) {
  let magicNumbers = [];

  for (let i = start; i <= end; i++) {
    if (isMagicNumber(i)) {
      magicNumbers.push(i);
    }
  }

  return magicNumbers;
}

// Display magic numbers in the range 1 to 50
const magicNumbersInRange = findMagicNumbersInRange(1, 50);

console.log(`Magic Numbers in the range 1 to 50:\n ${magicNumbersInRange.join(' ')}`);

💻 Testing the Program

Output

Magic Numbers in the range 1 to 50:
1 10 19 28 37 46

Run the script to check for magic numbers in the range from 1 to 50.

🧠 How the Program Works

The program defines a function isMagicNumber that checks if a given number is a magic number.
Inside the function, it uses a while loop to repeatedly sum the digits of the number until a single-digit result is obtained.
The findMagicNumbersInRange function iterates through the range from 1 to 50 and identifies magic numbers using the isMagicNumber function.
The program then displays the magic numbers in the specified range.

🧐 Understanding the Concept of Magic Numbers

A magic number is a number in which the sum of its digits leads to a single-digit number, and that single-digit number is 1.

For example, the number 19 is a magic number because the sum of its digits (1 + 9) is 10, and the sum of 1 and 0 is 1.

🎢 Optimizing the Program

While the provided program is effective, consider exploring and implementing optimizations or additional features based on your specific requirements.

Feel free to incorporate and modify this code as needed for your specific use case. Happy coding!