note 37134 added to function.eval

To evaluate math expressions (multiply, divide, addition, subtraction, percentages), use the following function, based on Taras Young's 'evalsum' function posted earlier: function matheval($equation){ $equation = preg_replace("/[^0-9+\-.*\/()%]/","",$equation); $equation = preg_replace("/([+-])([0-9]+)(%)/","*(1\$1.\$2)",$equation); // you could use str_replace on this next line // if you really, really want to fine-tune this equation $equation = preg_replace("/([0-9]+)(%)/",".\$1",$equation); if ( $equation == "" ) { $return = 0; } else { eval("\$return=" . $equation . ";"); } return $return; } You could easily extend this to include exponents, square roots, or really any other mathematical function. I use it in a 'price each' field on a purchase order form. The user can type in '$10.00-25%' and get 7.50 as the result. ---- Manual Page -- http://www.php.net/manual/en/function.eval.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+37134 Delete -- http://master.php.net/manage/user-notes.php?action=delete+37134&report=yes Reject -- http://master.php.net/manage/user-notes.php?action=reject+37134&report=yes Search -- http://master.php.net/manage/user-notes.php