PHP Warning: Division by zero
Try using
$var = @($val1 / $val2);
$diffPricePercent = (($actual * 100) / $itemCost) / $itemQty;
$itemCost
and $itemQty
are returning null
or zero, check them what they come with to code from user input
also to check if it's not empty data add:
if (!empty($_POST['num1'])) {
$itemQty = $_POST['num1'];
}
and you can check this link for POST validation before using it in variable
https://www.virendrachandak.com/techtalk/php-isset-vs-empty-vs-is_null/
If a variable is not set then it is NULL
and if you try to divide something by null you will get a divides by zero error
You need to wrap your form processing code in a conditional so it doesn't run when you first open the page. Something like so:
if($_POST['num1'] > 0 && $_POST['num2'] > 0 && $_POST['num3'] > 0 && $_POST['num4'] > 0){
$itemQty = $_POST['num1'];
$itemCost = $_POST['num2'];
$itemSale = $_POST['num3'];
$shipMat = $_POST['num4'];
$diffPrice = $itemSale - $itemCost;
$actual = ($diffPrice - $shipMat) * $itemQty;
$diffPricePercent = (($actual * 100) / $itemCost) / $itemQty ;
}