function for multiplying total cost?

[crossfuse]

I'm trying to make a function to add 6% tax to the total cost which the user can type in the cost of an item. The outcome is supposed to include the shipping as well (which I've done),but using variables isn't my forte. I understand the concept of them but here's what I got so far.

 

http://cpsc.maconstate.edu/students/justin.ham/cost.html

 

<?php
print("<b>Thankyou!</b><br><br><br>");
$cost = $_POST["cost"];


$cost1 = $cost + 3;
$cost2 = $cost + 4;
$cost3 = $cost + 5;
$cost4 = $cost + 6;

if ($cost < 0) {
print("Your total cost is invalid");
}
   
   elseif ($cost <= 25) {
print("Your total cost,plus shipping, is $$cost1");
}
   elseif ($cost <= 50) {
    print("Your total cost,plus shipping, is $$cost2");
}

   elseif ($cost <= 75) {
   print("Your total cost,plus shipping, is $$cost3");
} 

   elseif ($cost > 75)  {
   print("Your total cost,plus shipping, is $$cost4");
}




?>

 

do i insert a function before the 'if' statement and what exactly would i put?

[jackpf]

If you want to add 6%, just multiply it by 1.06.

[crossfuse]

If you want to add 6%, just multiply it by 1.06.

i would but i need to make it a function...

[jackpf]

Ok then.

[crossfuse]

Ok then.

how would i multiply 6% using a function?

[jackpf]

function add_six_percent($number)
{
return $number * 1.06;
}

[.josh]

echo "<b>Thankyou!</b><br><br><br>";
$cost = $_POST["cost"];
if ($cost < 0) {
  $msg = "Your total cost is invalid";
} else {
  $shipping = array(3 => 25, 4 => 50, 5 => 75, 6 => 76);
  foreach ($shipping as $k => $val) {
    if ($cost <= $val) {
      $cost = ($cost * 1.06) + $k;
      $msg = "Your total cost, plus shipping, is $$cost";
      break;
    } // end if
  } // end foreach
} // end if..else
echo $msg;

[crossfuse]

function add_six_percent($number)
{
return $number * 1.06;
}

how would i make that work with my code?

[jackpf]

If you want to add six percent to a number, just do

 

$number = 2;
$number2 = add_six_percent($number);
echo $number; //outputs 2
echo $number2; //outputs 2.12