$re = '/(?<=,|^)[0.+-]+(?=0(?:,|$))|\.0+\b|\b0+(?=\.)/';
$str = '2.0,3.00,-4.0,0.00,-0.00,0.03,2.01,0.001,-0.03,101';
$subst = "";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php