php - "Undefined variable: Profit $sum-$sub"

Question

I am attempting to make a sales report function for my database website, and I want to generate a profit value. Here is the method I am using:

function total_price($totals)
{
  $sub = 0;
  foreach ($totals as $total)
  {
    $sum += $total['total_saleing_price'];
    $sub += $total['total_buying_price'];
    $profit = $sum - $sub;

However, I get an error

UNDEFINED VARIABLE: PROFIT.

Can anyone help?

Answer 1

Assign $profit = 0 out of loop.

Also validate totals before iterating.

if(is_array($totals)){
  foreach($totals as $total ){
    // write your code here
  }
}