annoying math problem

[rross46]

hi. i got a few maths calculations in a script of mine. only it seems wen using multiplications, it dont like it.

     $nproduction_lvl=$tmember['unit_production']+1;
     $nnext_lvl=$tmember['next_lvl']+1;
     $addition=$nproduction_lvl+($nproduction_lvl*60);
     $ncost=($cost*2)+$addition;

this is for updating stats in a table. originally i just had

$ncost=$cost*2

but it was just set to 0. now, it goes up by 61.....it seems to totaly ignore the multiplications. what am i doing wrong here?

[mrhappiness]

what is the vars' content and how did you verify that?

[dalecosp]

rross46 wrote:

what am i doing wrong here?

multiplying by zero, most likely 🙂

mrhappiness wrote:

The last good thing written in C....

And it, like so many projects, remains only half-finished to this day....

[rross46]

right well its using a table called user_training.

it has production_lvl, next_lvl and cost.

the defaults for them are 1,2,100.

that code there sets nproduction_lvl to 2. nnext_lvl to 3. it should then set cost to 2+(260)+(1002). which is 322. but all it does is adds 60, or 61. cant remember. its like neglecting the multiplicaiton.

nproduction_lvl and nnext_lvl work, those fields update.

EDIT noticed another prob.-

    $new_user_gold=$user_gold-$cost; 
echo"$new gold is  $new_user_gold";

this $new_user_gold is used with another table to update the users gold after they used it to upgrade. it too gets set to 0. $user_gold=500. i checked this and it is set to that. $cost=100. i checked this too, it is set to that. but when i do the above, it dont work.

EDIT:

$new_user_gold is set to 0....

also above, when i had cost as $cost=$cost*2, it was set to 0. wasnt till i added that addition part in that it used other numbers.

[dalecosp]

[564] Mon 01.Aug.2005 10:12:07 
[kadmin@archangel][~/scripts]
cat bar
<?php
   $cost=100;
   $addition=61;
   $ncost=$cost*2+$addition;
   echo "ncost is $ncost
";
?>

[565] Mon 01.Aug.2005 10:12:10
[kadmin@archangel][~/scripts]
php bar
ncost is 261

With hard coded values, there isn't an issue. You must track down your variables....

[rross46]

yea multiplication by 0 is the prob. the second i go to use any math operations, the vars are set to 0. shdnt do that though...i mean i read em in from the table and displayed them. seemed fine. right until i go use the vars....

[dalecosp]

OK; PHP is a "weakly typed" language. Which means it's possible for $var to be a string such that "echo $var" shows a value, but ($var2 == 02) because PHP can't multiply by a string (and neither can I*).

Try using [man]print_r[/man] instead of [man]echo[/man], and see what type PHP thinks your vars are. It may be that the database types are wrong ...

[edit] * But alas, some programmers moan because they don't get any errors from the compiler/parser when they try to do this.... Incidentally, this "weak typing" is both a weakness (as we may find here) and a strength of PHP's design....[/edit]

[rross46]

right so there no easy answer to this....lol

hmm

right the vara $user_gold. i print_r it at the start, same with $gold. they r ok.

after i click upgrade, there is a blank value for them. not as 0, but nothing.

$new_user_gold is set to 0, and $ncost is $ncost.....

just did used is_int(); on my vars. says they not ints....the data from the db are ints....how do i make em ints? $user_gold and $cost aint ints. $new_user_gold is though.
its as soon as i put the db data into them they stop being ints....

<?
(!defined('')) ? die : '';
(!isset($_SESSION['user_id'])) ? redirect('index.php?mode=login') : '';
if (!@isset($_GET['upgrading']))
{
  $user_id=$_SESSION['user_id'];
  $tresult= mysql_query("SELECT * FROM `user_training`
                      WHERE user_id = $user_id");
if ($train=mysql_fetch_assoc($tresult)){
$cost=$train["production_cost"];
echo " produciton cost gold is $cost /";print_r($cost);echo' / ';
}else{
echo 'cant set user gfold';
}
if ($tresult)
{
  echo 'tresult successful';
}else{
  echo 'tresult failed';
}
  $result = mysql_query("SELECT * FROM `users`
                      WHERE user_id = '".$user_id."'");
if ($user=mysql_fetch_assoc($result)){
$user_gold=$user["user_gold"];
echo " user gold is $user_gold / ";print_r($user_gold);echo' / ';
}else{
echo 'cant set user gfold';
}
if ($result)
{
  echo 'result successful';
}else{
  echo 'result failed';
}
echo '<table width="90%" cellpadding="0" cellspacing="0" border="0">
       <tr>
             <td align="left"><b>Unit Production</b></td>
             <td align="left"><b>Next Level</b></td>
             <td align="left"><b>Cost</b></td>
       </tr>';
while ($tmember = mysql_fetch_assoc($tresult))
{
        echo '<tr>
                     <td align="left">'.$tmember['unit_production'].'</td>
             <td align="left">'.$tmember['next_lvl'].'</td>
                 <td align="left">'.$tmember['production_cost'].'</td>
            </tr>';
}
echo '</table>';
   echo '
<form action="index.php?mode=training&amp;upgrading=trueamp;" method="POST">
                   Upgrade:  <input type="submit" value="Upgrade" />
                     <input type="hidden" name="Upgrade" value="true" />
</form>';
} else if (@isset($_GET['upgrading'])) {
$tresult= mysql_query("SELECT * FROM `user_training`
                      WHERE user_id = '".$user_id."'");
$tmember = mysql_fetch_assoc($tresult)or die('an error occured in this query:'.$tresult.'. The error is: '.mysql_error()) ;
echo' // ';print_r($user["user_gold"]);echo' // ';
echo' // ';print_r($train["production_cost"]);echo' // ';
  if ($user_gold>=$cost)
  {
    $new_user_gold=$user["user_gold"]-$train["production_$cost"];
echo "new gold is  $new_user_gold / ";
print_r($new_user_gold);echo'/';
     $nproduction_lvl=$tmember['unit_production']+1;
     $nnext_lvl=$tmember['next_lvl']+1;  

$addition=$nproduction_lvl+($nproduction_lvl*82);
     $ncost=addition+($cost*2);
echo "new cost is $ncost / ";
print_r(ncost); echo'/';
     $user_result = mysql_query("UPDATE `users`
                                         SET user_gold = '".$new_user_gold."'
                                        WHERE user_id = '".$_SESSION['user_id']."'");

 $tuser_result=mysql_query("UPDATE `user_training`
                                    SET unit_production = '".$nproduction_lvl."',
                                    next_lvl = '".$nnext_lvl."',
                                     production_cost =$ncost
                                    WHERE user_id = '".$_SESSION['user_id']."'");

   }else{
     echo 'Not enough gold';
     timed_redirect('index.php?mode=training', 5);
}

if ($user_result)
{
  echo 'Upgrade Successful!';
  timed_redirect('index.php?mode=training', 5);
}else{
  echo 'Error Occurred1';
  timed_redirect('index.php?mode=training', 5);
}

if ($tuser_result)
{
  echo 'Upgrade Successfu22l!';
  timed_redirect('index.php?mode=training', 5);
}else{
  echo 'Error Occurre2d: '.$tuser_result.'. The error is: '.mysql_error();
  timed_redirect('index.php?mode=training', 5);
}
}
?>