PHP Program to Check Harshad Number

Posted in PHP Tutorial

Updated on Jan 11, 2024

By Mari Selvan

👁️ 31 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In the realm of programming, a Harshad number (or Niven number) is a positive integer that is divisible by the sum of its digits. Checking for Harshad numbers involves finding the sum of the digits and determining if the original number is divisible by this sum.

In this tutorial, we will explore a PHP program designed to check whether a given number is a Harshad number.

📄 Example

Let's delve into the PHP code that accomplishes this task.

isHarshadNumber.php

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<?php
// Function to check if a number is a Harshad number
function isHarshadNumber($number)
{
  $originalNumber = $number;
  $sumOfDigits = 0;

  // Calculate the sum of digits
  while ($number > 0)
  {
    $sumOfDigits += $number % 10;
    $number = (int)($number / 10);
  }

  // If the original number is divisible by the sum of digits, it is a Harshad number
  return ($originalNumber % $sumOfDigits == 0);
}

// Driver program
// Replace this value with the number you want to check
$number = 18;

// Call the function to check if the number is a Harshad number
if (isHarshadNumber($number))
{
  echo "$number is a Harshad number.\n";
}
else
{
  echo "$number is not a Harshad number.\n";
}
?>

💻 Testing the Program

To test the program with different numbers, modify the value of $number in the code.

Output

18 is a Harshad number.

Run the script to check if the specified number is a Harshad number.

🧠 How the Program Works

The program defines a function isHarshadNumber that takes an integer $number as input and returns true if the number is a Harshad number, and false otherwise.
Inside the function, it calculates the sum of the digits by iterating through the digits of the number.
If the original number is divisible by the sum of digits, the function returns true, indicating a Harshad number.
Inside the main program, replace the value of $number with the desired number you want to check.
The program calls the isHarshadNumber function and prints the result.

📏 Between the Given Range

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

isHarshad.php

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<?php
// Function to check if a number is a Harshad number
function isHarshad($number)
{
  $sum = array_sum(str_split($number));
  return ($number % $sum == 0);
}

// Range to check for Harshad numbers
$rangeStart = 1;
$rangeEnd = 20;

echo "Harshad numbers in the range $rangeStart to $rangeEnd:\n";

// Loop through the range and check for Harshad numbers
for ($i = $rangeStart;$i <= $rangeEnd;$i++)
{
  if (isHarshad($i))
  {
    echo "$i ";
  }
}

?>

💻 Testing the Program

Output

Harshad numbers in the range 1 to 20:
1 2 3 4 5 6 7 8 9 10 12 18 20

Simply run the script to see the Harshad numbers in the range from 1 to 20.

🧠 How the Program Works

The program defines a function isHarshad that takes a number as input and checks if it's a Harshad number.
Inside the function, it calculates the sum of the digits using array_sum and str_split.
It then checks if the number is divisible by the sum of its digits.
The main section loops through the specified range (1 to 20) and prints Harshad numbers.

🧐 Understanding the Concept of Harshad Number

Before delving into the code, let's understand the concept of Harshad numbers. A Harshad number is a positive integer that is divisible by the sum of its digits.