php sum variable in while loop

Question

I have to "sum" variable's values in while, here us my example :

while($row = mysql_fetch_array($result)){
  $price= $row['price'] * $row['order_q'];
}

The code above will output if I put echo $price; for example:

19 15 20 13 10

I want something like : sum($price) or array_sum($price) to count all the results of while loop. So, that i want to count: 19+15+20+13+10 = 77

How can I do it with php?

Thanks

Answer 1

Simply initialize a variable outside your loop for example:

$total_price = 0;

and increment this number inside your loop:

$total_price += $row['price'] * $row['order_q'];