PHP Exercises: Compute the sum of the digits of a number

PHP: Exercise-45 with Solution

Write a PHP program to compute the sum of the digits of a number.

Sample Solution:

PHP Code:

<?php
// Define a function to calculate the sum of digits in a given number
function sum_of_digits($nums) {
    // Initialize a variable to store the sum of digits
    $digits_sum = 0;

    // Iterate through each digit in the number
    for ($i = 0; $i < strlen($nums); $i++) {
        // Add the current digit to the sum
        $digits_sum += $nums[$i];
    }

    // Return the sum of digits
    return $digits_sum;
}

// Test the function with example numbers
echo sum_of_digits("12345")."\n";
echo sum_of_digits("9999")."\n";

?>

Explanation:

• Function Definition:
• The function sum_of_digits($nums) is defined to calculate the sum of the digits of a given number passed as a string.
• Initialize Sum Variable:
• A variable $digits_sum is initialized to 0 to hold the cumulative sum of the digits.
• Iterate Through Digits:
• A for loop iterates through each character in the string $nums using the length of the string (strlen($nums)) as the loop's limit.
• The loop variable $i represents the current index of the character being processed.
• Add Each Digit:
• Inside the loop, the current digit (as a character) is accessed using $nums[$i] and added to the $digits_sum variable.
• Since the digits are passed as a string, PHP automatically converts the character to its integer value when performing the addition.
• Return the Result:
• After the loop completes, the function returns the total sum of the digits.
• Test Cases:
• The function is tested with two example inputs:
• sum_of_digits("12345"), which calculates 1 + 2 + 3 + 4 + 5, resulting in 15.
• sum_of_digits("9999"), which calculates 9 + 9 + 9 + 9, resulting in 36.
• The results are printed to the output.

Output:

15                                                          
36

Flowchart:

PHP Code Editor:

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