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PHP Exercises: Check whether a number is an Armstrong number or not

PHP: Exercise-32 with Solution

Write a PHP program to check whether a number is an Armstrong number or not. Return true if the number is Armstrong otherwise return false.

An Armstrong number of three digits is an integer so that the sum of the cubes of its digits is equal to the number itself. For example, 153 is an Armstrong number since 1**3 + 5**3 + 3**3 = 153

Sample Solution: -

PHP Code:

<?php
function armstrong_number($num) {
  $sl = strlen($num);
  $sum = 0;
  $num = (string)$num;
  for ($i = 0; $i < $sl; $i++) {
    $sum = $sum + pow((string)$num{$i},$sl);
  }
  if ((string)$sum == (string)$num) {
    return "True";
  } else {
    return "False";
  }
}
echo "Is 153 Armstrong number? ".armstrong_number(153);
echo "\nIs 21 Armstrong number? ".armstrong_number(21);
echo "\nIs 4587 Armstrong number? ".armstrong_number(4587);"\n";
?>

Sample Output: 

Is 153 Armstrong number? True                                          
Is 21 Armstrong number? False                                          
Is 4587 Armstrong number? False

Flowchart:

Flowchart: Check whether a number is an Armstrong number or not

PHP Code Editor:

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PHP: Tips of the Day

Mutates the original array to filter out the values specified

Example:

<?php
function tips_pull(&$items, ...$params)
{
  $items = array_values(array_diff($items, $params));
  return $items;
}

$items = ['x', 'y', 'z', 'x', 'y', 'z'];
print_r(tips_pull($items, 'y', 'z'));
?>

Output:

Array
(
    [0] => x
    [1] => x
)