JavaScript Program to find Composite Number

Posted in JavaScript Tutorial

Updated on Oct 30, 2024

By Mari Selvan

👁️ 918 - Views

⏳ 4 mins

💬 1 Comment

JavaScript Program to find Composite Number

Photo Credit to CodeToFun

🙋 Introduction

In the realm of programming, identifying and working with different types of numbers is a fundamental skill.

A composite number is one that has more than two positive divisors, excluding 1 and itself. In this tutorial, we'll explore a javascript program that efficiently determines whether a given number is composite or not.

📄 Example

Let's dive into the javascript code that checks whether a number is composite or not.

isCompositeNumber.js

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// Function to check if a number is composite
function isCompositeNumber(number) {
  if (number <= 1) {
    return false;
  }

  for (let i = 2; i <= Math.sqrt(number); i++) {
    if (number % i === 0) {
      return true; // Found a divisor other than 1 and itself
    }
  }

  return false; // Number is not divisible by any number other than 1 and itself
}

// Driver program
// Replace this value with your desired number
const inputNumber = 12;

// Check if the input number is composite
if (isCompositeNumber(inputNumber)) {
  console.log(`${inputNumber} is a composite number.`);
} else {
  console.log(`${inputNumber} is not a composite number.`);
}

💻 Testing the Program

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

Output

12 is a composite number.

Run the script to see whether the input number is a composite number.

🧠 How the Program Works

The program defines a function isCompositeNumber that takes a number as input and returns true if the number is composite and false otherwise.
Inside the function, it first checks if the number is less than or equal to 1. If so, it returns false since 1 and numbers less than 1 are not considered composite.
It then iterates from 2 to the square root of the input number. For each iteration, it checks if the number is divisible by the current value of i. If it is, the function returns true, indicating that the number has a divisor other than 1 and itself.
If no such divisor is found during the iteration, the function returns false, indicating that the number is not a composite number.

📏 Between the Given Range

Let's take a look at the JavaScript code that identifies composite numbers in the specified range.

isComposite.js

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// Function to check if a number is composite
function isComposite(number) {
  if (number <= 1) {
    return false;
  }

  for (let i = 2; i <= Math.sqrt(number); i++) {
    if (number % i === 0) {
      return true; // Number has a divisor other than 1 and itself
    }
  }

  return false; // Number is not composite
}

// Check for composite numbers in the range 1 to 10
console.log("Composite numbers in the range 1 to 10:");

for (let i = 1; i <= 10; i++) {
  if (isComposite(i)) {
    console.log(i);
  }
}

💻 Testing the Program

Output

Composite numbers in the range 1 to 10 are: 
4 6 8 9 10

Run the script to see the composite numbers in the range from 1 to 10.

🧠 How the Program Works

The program defines a function isComposite that checks if a given number is composite.
Inside the function, it checks for divisors from 2 up to the square root of the number.
If a divisor is found, the number is composite; otherwise, it is not.
The main section then checks for composite numbers in the range from 1 to 10 using the isComposite function.

🧐 Understanding the Concept of Composite Numbers

Composite numbers are integers greater than 1 that have divisors other than 1 and themselves.

For example, the number 12 is composite because it can be formed by multiplying 2 and 6 or 3 and 4.

🎢 Optimizing the Program

While the provided program is effective, consider exploring and implementing optimizations for larger numbers, such as checking divisors up to the square root of the number for improved efficiency.

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