else if statement problem

[jacobsultd]

Hello,

 Got a problem. I have an ecomm site and am close to deployment but running into a problem.. In calculating shipping cost, I am basing the shipping by the number of items.. I wrote this elseif code (methodical I know),

function shipping()
{
$dozen = 20.00;
$half = 15.95;
$add = 10.95;
$items = $_SESSION['items'];

if ($items <= 6) {
return $half;}
elseif (($items > 6) <= 12){
return $dozen;}
elseif (($items > 12) <= 18){
return $dozen 2; }
elseif (($items > 18) <= 24){
return $dozen 2;}
elseif (($items > 24) <= 30){
return ($dozen 2) + $add;}
elseif (($items > 30) <= 36){
return $dozen 3;}
elseif (($items > 36) <= 42){
return ($dozen 3) + $add;}
elseif (($items > 42) <= 48){
return $dozen 4;}
elseif (($items > 48) <= 54){
return ($dozen 4) + $add;}
elseif (($items > 54) <= 60){
return $dozen 5;}
elseif (($items > 60) <= 66){
return ($dozen 5) + $add;}
elseif (($items > 60) <= 72){
return $dozen 6;}
elseif (($items > 72) <= 78){
return ($dozen 6) + $add;}
elseif (($items > 78) <= 84){
return $dozen 7;}
}

When I test this code, with items = 6, I get the right value. Items = 12, I get the right number. But when the number is greater than 12, php does not parse any further than the first two conditions.

if ($items <= 6) {
return $half;}
elseif (($items > 6) <= 12){
return $dozen;}

I tried case statement as well, but same results, gets to second case and stops:

<?php

$items = 13;

function test($items){
$dozen = 20.00;
$half = 15.95;
$add = 10.95;

switch($items) {
case ($items <= 6):
return $half;
break;
case (($items > 6) <= 12):
return $dozen;
break;
case (($items > 12) <= 18):
return $add;
break;
}
}
echo test($items);
?>

Can anyone help me out? or give me an easier way. Thanks..

-Andre

[LordShryku]

Well, easier would be to use a switch statement. It's a little cleaner too. You may have put a little too much though into the logic.

# Like
elseif (($items > 18) <= 24){ 
# would really be written
elseif ($items > 18 && $items <= 24){
# but the check for 18 isn't neccesary, because if that was false, 
# it would have already been picked up in your previous checks.

# So here's what I would do...
switch(TRUE) {
   case ($items <= 6):  return $half;                 break;
   case ($items <= 12): return $dozen;                break;
   case ($items <= 18): return ($dozen * 2);          break;
   case ($items <= 30): return (($dozen * 2) + $add); break;
   # and so on and so forth
}

Just as a note, the reason it was always returning on the second one is because you were evaluating a boolean value instead of the number.

# In numeric value for boolean, TRUE = 1 and FALSE = 0
# So assuming the number is 36 or something, you break down
# your comparison by parens

elseif (    ($items > 6)     <= 12)
# really does  ($items > 6) first, which equates to true, or 1,
# so the second comparison is really always looking like this
elseif (    1     <= 12)
# which would always return true

[Fructose]

I believe this will fix your problem, you were trying to get a value between two ranges, however the second value you were comparing to was evaluating in relation to $items

your statement if (($items >= 6) < 12)
was comparing $items >= 6 AND $items < 12, therefor since $items is in fact < 12 the statement would be true reguardless if $items was <=6.

Elseif statements will stop when the first condition met it true. here is the working code, hope this helps:

 
$dozen = 20.00;
$half = 15.95;
$add = 10.95;
$items = $_SESSION['items'];

if ($items <= 6) {
return $half;
}
elseif ($items < 12){
return $dozen;
}
elseif ($items < 18){
return $dozen * 2;
}
elseif ($items < 24){
return $dozen * 2;
}
elseif ($items < 30){
return $dozen * 2 + $add;
}
elseif ($items < 36){
return $dozen * 3;
}
elseif ($items < 42){
return $dozen * 3 + $add;
}
elseif ($items < 48){
return $dozen * 4;
}
elseif ($items < 54){
return $dozen * 4 + $add;
}
elseif ($items < 60){
return $dozen * 5;
}
elseif ($items < 66){
return $dozen * 5 + $add;
}
elseif ($items < 72){
return $dozen * 6;
}
elseif ($items < 78){
return $dozen * 6 + $add;
}
elseif ($items < 84){
return $dozen * 7;
}

[jacobsultd]

Thanks guys, I used LordShryku code.. but both suggestions showed me the errors of my beginners ways. Thanks.. I'll come up with another issue soon..