Regular expression to only allow whole numbers and commas in a string

Question

Does anyone know what the preg_replace would be for a string to only allow whole numbers and commas? I want to strip all whitespace, letters, symbols, etc, so all that is le

Answer 1

This is a the function I came up with, with everyone's help. It works fine for commas, but not any other delimiters.

if (!function_exists('explode_trim_all')) {
  function explode_trim_all($str, $delimiter = ',') {
    if ( is_string($delimiter) ) {
      $str = preg_replace(
        array(
          '/[^\d'.$delimiter.']/', // Matches anything that's not a delimiter or number.
          '/(?<='.$delimiter.')'.$delimiter.'+/', // Matches consecutive delimiters.
          '/^'.$delimiter.'+/',                   // Matches leading delimiters.
          '/'.$delimiter.'+$/'                    // Matches trailing delimiters.
        ),
        '',              // Remove all matched substrings.
        $str
      );
      return explode($delimiter, $str);
    }
    return $str;
  }
}