$totalSum = 0;

// Product 1
$productName1 = ‘Product Name 1’;
$unitPrice1 = 10;
$totalSum += $unitPrice1;

// Product 2
$productName2 = ‘Product Name 2’;
$unitPrice2 = 20;
$totalSum += $unitPrice2;

// Product n…
// Add more product variables and unit prices here

return “The total sum of all products is: ” . $totalSum;