online quiz using php and mysql(radio button) - php

Question

please help, i'm developing an online quiz application. All the questions and answers will be selected from the database. Where i'm having probkem with is to get the values from the radio button whether checked or not. bellow is the code that generate the questions and answers from database.
if (!isset($_POST['submit'])) {
echo "<form method=post action='#'>";
echo "<table border=0>";
while ($row = mysql_fetch_array($display)) {
$id = $row["id"];
$question = $row["question"];
$opt1 = $row["ans1"];
$opt2 = $row["ans2"];
$opt3 = $row["ans3"];
$opt4 = $row["ans4"];
$opt5 = $row["ans5"];
$answer = $row["ans"];
echo "<tr><td colspan=3><br><b>$question</b></td></tr>";
echo "<tr><td>$opt1 <input type=radio name=q$id value=\"$opt1\"></td><td>$opt2 <input type=radio name=q$id value=\"$opt2\"></td><td>$opt3 <input type=radio name=q$id value=\"$opt3\"></td><td>$opt4 <input type=radio name=q$id value=\"$opt4\"></td><td>$opt5 <input type=radio name=q$id value=\"$opt5\">q$id</td></tr>";
}
echo "</table>";
echo "<input type='submit' value='See how you did' name='submit'>";
echo "</form>";
}
the name of the radio button is
<input type='radio' name='q$id' value='$opt4' />
How do i get the value of the checked radio button?
or is my PHP code wrong?
what i needed is to output what is selected if a radio button is checked.
if(isset($_POST['submit']))
{
$value = $_POST[''];//the value of the radio button, i don't know what to put here
$n = count($value);
for($i=0; $i < $n; $i++)
{
echo $value[$i];
}
}

Answer 1

Try:
if(isset($_POST['submit']))
{
$value = $_POST;//the value of the radio button, i don't know what to put here
$n = count($value);
for($i=0; $i < $n; $i++)
{
echo $value[$i];
}
}
$_POST[''] was wrong. You needed to use just $_POST.
You could also just use foreach here:
if(isset($_POST['submit']))
{
$values = $_POST;//the value of the radio button, i don't know what to put here
foreach($values as $value)
{
echo $value;
}
}
$_POST is just a array containing whatever your form submited. If you had a name textfield you would use:
echo $_POST['name'];
to echo it.
Try
var_dump("<PRE>", $_POST);
And you will see exactly how your form is being organised. Link to documentation

Answer 2

thanks for your response. i was able to come out with this code and it works but i don't know if the structure or the way i solved it is proper or good enough.
<?php
if (!isset($_POST['submit'])) {
echo "<form method=post action='#'>";
echo "<table border=0>";
while ($row = mysql_fetch_array($display)) {
$id = $row["id"];
$question = $row["question"];
$opt1 = $row["ans1"];
$opt2 = $row["ans2"];
$opt3 = $row["ans3"];
$opt4 = $row["ans4"];
$opt5 = $row["ans5"];
$answer = $row["ans"];
echo "<tr><td colspan=3><br><b>$question</b></td></tr>";
echo "<tr><td><input type=radio name=$id value=\"$id $opt1\">$opt1 </td><td><input type=radio name=$id value=\"$id $opt2\">$opt2 </td><td><input type=radio name=$id value=\"$id $opt3\">$opt3 </td><td><input type=radio name=$id value=\"$id $opt4\">$opt4 </td><td><input type=radio name=$id value=\"$id $opt5\">$opt5 <br>";
}
echo "</table>";
echo "<input type='submit' value='See how you did' name='submit'>";
echo "</form>";
}
?>
what i did was to include the id of the question in the value of the radio button
<input type=radio name=$id value=\"$id $opt1\">
i collect the values of the radio button using $_POST as suggested, i then explode the value into two arrays so the first array will contain the question id and the second will contain the actual value of the radio button (answer).
<?php
elseif (isset($_POST['submit']))
{
var_dump("<PRE>", $_POST);
$sd = $_POST;
foreach($sd as $sd)
{
$tok = explode(" ", $sd, 2);
$w = mysql_query("select * from `questions` WHERE `id` = '$tok[0]'")or die(mysql_error());
if(mysql_num_rows($w) == 1)
{
$sf = mysql_fetch_object($w);
echo $tok[1].".......".$sf->ans."<br>";
}
}
}
?>
it works perfectly but will it give efficient result?