Kommagetrennte Liste in ein Array umwandeln und jeden Wert validieren

source-00.php

<?php

function getFormatedArray($string) {
  $result = array();
  
  if (strpos($string, ',') !== false) {
    $substrings = explode(',', $string);
  
    foreach ($substrings as $substring) {
      if (trim($substring) != '') {
        $result[] = strtoupper(trim($substring));
      }
    }
  
    if (!count($result)) {
      return 'ERROR';
    }
  }
  else {
    $result[] = $string;
  }
  
  return $result;
}

source-01.php

<?php

$result = array();
if (strpos($string, ',') !== false) {
  $substrings = explode(',', $string);

  // [...]
}
else {
  $result[] = $string;
}

source-02.php

<?php

function getFormatedArray($string) {
  $result     = array();
  $substrings = explode(',', $string);
  
  foreach ($substrings as $substring) {
    if (trim($substring) != '') {
      $result[] = strtoupper(trim($substring));
    }
  }
  
  if (!count($result)) {
    return 'ERROR';
  }
  
  return $result;
}

source-03.php

<?php

function getFormatedArray($string) {
  $result = explode(',', $string);
  
  array_walk($result, function(&$substring, $key) {
    $substring = strtoupper(trim($substring));
  });
  
  if (!count($result)) {
    return 'ERROR';
  }
  
  return $result;
}