ID: 48904
User updated by: 7willows at dsl dot pipex dot com
Reported By: 7willows at dsl dot pipex dot com
-Status: Feedback
+Status: Open
Bug Type: Math related
Operating System: SunOS ts10 5.11 snv_115 i86pc
PHP Version: 5.2.10
New Comment:
<?php
function answerlength($maxnumberfacts) {
$maxvalue=$maxnumberfacts * $maxnumberfacts ;
$length=strlen($maxvalue);
return $length;
}
function setquestioncount($maxnumberfacts) {
switch($maxnumberfacts) {
case 2:
$count=10;
break;
case 3:
$count=20;
break;
case 4:
$count=20;
break;
case 5:
$count=20;
break;
case 6:
$count=20;
break;
case 7:
$count=20;
break;
case 8:
$count=20;
break;
case 9:
$count=20;
break;
case 10:
$count=20;
break;
case 11:
$count=20;
break;
case 12:
$count=20;
break;
case 13:
$count=20;
break;
case 14:
$count=20;
break;
case 15:
$count=20;
break;
case 16:
$count=20;
break;
case 17:
$count=20;
break;
case 18:
$count=20;
break;
case 19:
$count=20;
break;
case 20:
$count=20;
break;
}
return $count;
}
function multiplicationanddivision() {
$operator=rand(0,1);
if ($operator) {
return '/';
} else {
return '*';
}
}
function setnumberfacttest($count,$maxnumberfacts) {
global $numfacttest, $answer, $operator, $randval;
for ($a = 0 ; $a < $count ; $a++) {
$numfacttest[$a]=rand(0,$maxnumberfacts);
$randval[$a]=rand(0,$numfacttest[$a]);
$operator[$a]='x';
switch($operator[$a]) {
case 'x':
$answer[$a]=$numfacttest[$a] * $randval[$a];
break;
case '/':
$answer[$a]=$numfacttest[$a] * $randval[$a];
$tmp=$numfacttest[$a];
$numfacttest[$a]=$answer[$a];
$answer[$a]=$tmp;
break;
case '+':
$answer[$a]=$numfacttest[$a] - $randval[$a];
break;
case '-':
$answer[$a]=$numfacttest[$a] - $randval[$a];
break;
}
}
}
if (isset($_POST['mainmenu'])) {
header('Location: /education.php');
exit();
}
if (isset($_POST['changerange'])) {
header('Location: multiplicationwelcome.php');
exit();
}
if (isset($_POST['maxfacts'])) {
$maxnumberfacts=$_POST['maxfacts'];
$numfacttest[0]=0;
$answer[0]=0;
$operator[0]="x";
$randval[0]=0;
$questionlength=answerlength($maxnumberfacts);
$count=setquestioncount($maxnumberfacts);
setnumberfacttest($count,$maxnumberfacts);
include("edupageheader.php");
echo '<body>';
echo '<h1>Multiplication Number Facts to
',$maxnumberfacts,'</h1>';
echo 'Please answer the following questions...';
echo '<br /><br />';
echo '<form method="POST" action="multiplicationtables.php"
id="mathsform" />';
for ($a = 0; $a < $count; $a++) {
switch($operator[$a]) {
case 'x':
echo '<input type="text" name="val1ue',$a,'"
value="',$numfacttest[$a],'" readonly="readonly"
maxlength="',$questionlength,'" size="',$questionlength,'" />';
echo '<input type="text" name="operator',$a,'"
value="',$operator[$a],'" readonly="readonly"
maxlength="',$questionlength,'" size="',$questionlength,'" />';
echo '<input type="text" name="val2ue',$a,'"
value="',$randval[$a],'" readonly="readonly"
maxlength="',$questionlength,'" size="',$questionlength,'" />';
echo ' = ';
echo '<input type="text" name="useranswer',$a,'"
value="" maxlength="',$questionlength,'"size="',$questionlength,'" />';
echo '<input type="hidden" name="answer',$a,'"
value="',$answer[$a],'"/>';
echo "<br />";
break;
case '/':
echo '<input type="text" name="val1ue',$a,'"
value="',$numfacttest[$a],'" readonly="readonly"
maxlength="',$questionlength,'"size="',$questionlength,'" />';
echo '<input type="text" name="operator',$a,'"
value="',$operator[$a],'" readonly="readonly"
maxlength="',$questionlength,'" size="',$questionlength,'" />';
echo '<input type="text" name="val2ue',$a,'"
value="',$randval[$a],'" readonly="readonly"
maxlength="',$questionlength,'" size="',$questionlength,'" />';
echo ' = ';
echo '<input type="text" name="useranswer',$a,'"
value="" maxlength="',$questionlength,'"size="',$questionlength,'" />';
echo '<input type="hidden" name="answer',$a,'"
value="',$answer[$a],'"/>';
echo "<br />";
break;
}
}
echo '<br />';
echo '<input type="submit" name="checkanswers" value="check
answers" />';
echo '<input type="submit" name="changerange" value="change
number facts" />';
echo '<input type="submit" name="mainmenu" value="main
menu" />';
echo '<input type="hidden" name="questions"
value="',$count,'" />';
echo '<input type="hidden" name="maxsum"
value="',$maxnumberfacts,'" />';
echo '</form>';
echo '</body>';
echo '</html>';
exit();
}
if (isset($_POST['checkanswers'])) {
$count=$_POST['questions'];
$maxnumberfacts=$_POST['maxsum'];
include("edupageheader.php");
echo '<body>';
echo '<h1>Multiplication Number Facts to
',$maxnumberfacts.'</h1>';
for ($a=0 ; $a < $count ; $a++) {
$part1="val1ue" . $a ;
$part2="val2ue" . $a ;
$part3="useranswer" . $a ;
$part4="answer" . $a ;
$part5="operator" . $a ;
$value_a=$_POST[$part1];
$value_b=$_POST[$part2];
$value_c=$_POST[$part3];
$value_d=$_POST[$part4];
$value_e=$_POST[$part5];
switch($value_e) {
case 'x':
echo "<tr> <td>",$value_a,"</td><td> ",$value_e,"
</td><td>",$value_b,"</td><td> = </td><td>",$value_c,"</td>" ;
break;
case '/':
echo "<tr> <td>",$value_a,"</td><td> ",$value_e,"
</td><td>",$value_b,"</td><td> = </td><td>",$value_c,"</td>" ;
break;
}
if ($value_c == $value_d) {
echo "<td> correct! </td></tr";
} else {
echo "<td> wrong! </td></tr>";
}
echo "<br />";
echo "<br />";
}
echo '<form method="POST" action="multiplicationtables.php"
id="mathsform" />';
echo '<input type="submit" name="morequestions" value="more
questions" />';
echo '<input type="submit" name="changerange" value="change number
facts" />';
echo '<input type="submit" name="mainmenu" value="main menu" />';
echo '<input type="hidden" name="maxfacts"
value="',$maxnumberfacts,'"/>';
echo '</form>';
echo '</body>';
echo '</html>';
}
exit();
?>
Previous Comments:
------------------------------------------------------------------------
[2009-07-13 19:02:25] j...@php.net
Thank you for this bug report. To properly diagnose the problem, we
need a short but complete example script to be able to reproduce
this bug ourselves.
A proper reproducing script starts with <?php and ends with ?>,
is max. 10-20 lines long and does not require any external
resources such as databases, etc. If the script requires a
database to demonstrate the issue, please make sure it creates
all necessary tables, stored procedures etc.
Please avoid embedding huge scripts into the report.
------------------------------------------------------------------------
[2009-07-13 13:51:32] 7willows at dsl dot pipex dot com
Description:
------------
I have a function which is used to assign values into a number of
global arrays. Two of the arrays are assigned values that are generated
using the rand() function. A third array holds the result of the
multiplication. When both first two arrays are assigned a value of 0
(zero), the result of the multiplication is 1 and not 0.
This information is then entered into a html form and presented to the
user and they are asked to enter the results of
$numfacttest[$a] / $randval[$a] = useranswer
The useranswer is then compared to $answer[$a] which is already
calculated. The problem is that 0 * 0 is returning the answer 1
sometimes.
Reproduce code:
---------------
function setnumberfacttest($count,$maxnumberfacts) {
global $numfacttest, $answer, $operator, $randval;
for ($a=0 ; $a < $count ; $a++) {
$operator[a]=chr(247);
$bit1=rand(0,$maxnumberfacts);
$bit2=rand(0,$maxnumberfacts);
$numfacttest[$a]=$bit1 * $bit2;
$randval[$a]=$bit2;
$answer[$a]=$bit1;
}
}
Expected result:
----------------
Actual Results with hidden value displayed
2 / 1 = <useranswer> 2
0 / 0 = <useranswer> 0
0 / 0 = <useranswer> 0
2 / 2 = <useranswer> 1
4 / 2 = <useranswer> 2
1 / 1 = <useranswer> 1
0 / 0 = <useranswer> 0
0 / 0 = <useranswer> 0
0 / 0 = <useranswer> 0
1 / 1 = <useranswer> 1
Actual result:
--------------
Actual Results with calculated hidden value displayed
2 / 1 = <useranswer> 2
0 / 0 = <useranswer> 1
0 / 0 = <useranswer> 0
2 / 2 = <useranswer> 1
4 / 2 = <useranswer> 2
1 / 1 = <useranswer> 1
0 / 0 = <useranswer> 1
0 / 0 = <useranswer> 0
0 / 0 = <useranswer> 2
1 / 1 = <useranswer> 1
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=48904&edit=1
