Write a PHP program to print sum of digits

Here we are write a program to find sum of digits of a given number, for the sum of digits we have to add all the digits of given number.

Logical Part of program:

1. First you have to take the number.
2. Then divide the taken number by 10.
3. Store the remainder into a variable.
4. Final step repeat the process until remainder is 0.

Given program shows the sum of digits of 987654321.

PHP Logic Part:

1. Creating Three(3) PHP Variables. $num, $sum, $rem.
Variable $num will be store given numbers.
Variable $sum will be store total sum of digits.
Variable $rem will be store remainder of the number.
2. Then here we are using for loop for logical part, withing for loop we also use a php function strlen() to find length of numbers. ;enght of number we are checking with variable $i that was initialize by 0.

PHP Program of sum of digits

<?php
$num = 987654321;
$sum = 0;
$rem = 0;
for ($i =0; $i<=strlen($num);$i++)
{ 
 $rem=$num%10; 
 $sum = $sum + $rem;
 $num=$num/10;
}
echo "Sum of digits $num is $sum"; 
?>

PHP Program of sum of digits using HTML Form

<form method="post">
<input type="text" name="number" placeholder="Enter number" />
<input type="submit" value="Submit" />
</form>

<?php
if(isset($_POST['number']))
{
$onum = $_POST['number'];
$num = $_POST['number'];
$sum = 0;
$rem = 0;
for ($i =0; $i<=strlen($num);$i++)
{
$rem=$num%10;
$sum = $sum + $rem;
$num=$num/10;
}
echo "Sum of digits $onum is $sum";
}
?>