PHP Program to find Composite Number

Posted in PHP Tutorial

Updated on Jan 11, 2024

By Mari Selvan

👁️ 167 - Views

⏳ 4 mins

💬 1 Comment

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 php program that efficiently determines whether a given number is composite or not.

📄 Example

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

isComposite.php

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

  // Check for factors other than 1 and the number itself
  for ($i = 2;$i < $number;$i++)
  {
    if ($number % $i === 0)
    {
      return true;
    }
  }

  return false;
}

// Default input number
$defaultNumber = 12;

// Call the function to check if the default number is composite
$result = isComposite($defaultNumber);

// Output the result
if ($result)
{
  echo "$defaultNumber is a composite number.\n";
}
else
{
  echo "$defaultNumber is not a composite number.\n";
}

?>

💻 Testing the Program

To test the program with different numbers, simply replace the value of $defaultNumber with your desired input.

Output

12 is a composite number.

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

🧠 How the Program Works

The program defines a function isComposite that takes a number as input and returns true if it is a composite number and false otherwise.
Inside the function, it checks for factors other than 1 and the number itself by iterating through numbers from 2 to the number-1.
If any factor is found, the number is considered composite.
The default input number is set to 12, and the function is called to check whether it is a composite number.
The result is then echoed to the console.

📏 Between the Given Range

Let's delve into the PHP code that checks for composite numbers in the specified range.

isComposite.php

Copied

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

  // Check for divisors other than 1 and the number itself
  for ($i = 2;$i < $number;$i++)
  {
    if ($number % $i == 0)
    {
      return true;
    }
  }

  return false;
}

// Driver program to check for composite numbers in the range 1 to 10
echo "Composite numbers in the range 1 to 10 are: \n";

for ($i = 1;$i <= 10;$i++)
{
  if (isComposite($i))
  {
    echo "$i ";
  }
}

?>

💻 Testing the Program

Output

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

The provided program checks for composite numbers in the range 1 to 10. To test the program, simply run it.

🧠 How the Program Works

The program defines a function isComposite that checks whether a given number is composite.
Inside the function, it first checks if the number is less than or equal to 1 (not composite).
It then iterates through numbers from 2 to the number itself, checking for divisors other than 1 and the number itself.
The main section of the program tests and prints composite numbers in the range 1 to 10.

🧐 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!