Example of Euler function simple implementation of PHP

This article describes the simple implementation of Euler function Euler function in PHP. Share it for your reference, as follows:

Euler functionph(n) meansAll numbers smaller than n and co-equality with n。

For example ph(10) = 4{1,3,7,9 and 10}

The code is as follows:

<?php
function Euler($x)
{
  $res = $x;
  $now = 2;
  while ($x > 1) {
    if ($x % $now == 0) {
      $res /= $now;
      $res *= ($now - 1);
      while ($x % $now == 0) {
        $x /= $now;
      }
    }
    $now++;
  }
  return $res;
}
$res = Euler(10);
var_dump($res);
?>

Running results:

int(4)

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