JavaScript Program to find Number Combination

Posted in JavaScript Tutorial

Updated on Jan 11, 2024

By Mari Selvan

👁️ 85 - Views

⏳ 4 mins

💬 1 Comment

JavaScript Program to find Number Combination

Photo Credit to CodeToFun

🙋 Introduction

In the realm of programming, creating combinations of numbers is a common and useful task. A combination is a selection of items from a collection, where the order of selection does not matter.

In this tutorial, we'll explore a JavaScript program that efficiently generates combinations of two specified numbers within a given range.

📄 Example

Let's take a look at the JavaScript code that achieves this functionality.

generateCombinations.js

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// Function to calculate the number of digits in a number
function countDigits(num) {
  let count = 0;
  while (num !== 0) {
    num = Math.floor(num / 10);
    count++;
  }
  return count;
}

// Function to generate combinations of two numbers up to a specified limit
function generateCombinations(number1, number2, limit) {
  console.log(`List of combinations of ${number1} and ${number2} up to ${limit}:`);

  for (let i = 1; i <= limit; ++i) {
    let currentNumber = i;

    // Check if the current number contains only the specified digits
    while (currentNumber > 0) {
      const digit = currentNumber % 10;
      if (digit !== number1 && digit !== number2) {
        break;
      }
      currentNumber = Math.floor(currentNumber / 10);
    }

    // If the current number contains only the specified digits, log it
    if (currentNumber === 0) {
      process.stdout.write(`${i} `);
    }
  }

  console.log();
}

// Driver program
// Replace these values with your desired numbers and limit
const targetNumber1 = 4;
const targetNumber2 = 8;
const combinationLimit = 500;

// Call the function to generate combinations
generateCombinations(targetNumber1, targetNumber2, combinationLimit);

💻 Testing the Program

To test the program with different values, replace the values of targetNumber1, targetNumber2, and combinationLimit in the code.

Output

List of combinations of 4 and 8 up to 500:
4 8 44 48 84 88 444 448 484 488

Run the script to see the list of combinations.

🧠 How the Program Works

The program defines a function countDigits to calculate the number of digits in a given number.
The function generateCombinations generates combinations of two specified numbers up to a given limit.
Inside the function, it iterates through numbers from 1 to the specified limit.
For each iteration, it checks if the current number contains only the specified digits.
If the condition is met, the current number is a combination, and it is logged.

🧐 Understanding the Concept of Number Combination

Before delving into the code, let's take a moment to understand the concept of combinations. In mathematics, a combination is a selection of items from a collection, where the order of selection does not matter.

For example, consider the specified numbers as 4 and 8. The combinations of 4 and 8 up to 500 include 4, 8, 44, 48, 84, 88, 444, 448, 484, and 488.