[Resolved] Multi-dimensional $_POST

[terrym]

I have a PHP script which basically presents the viewer with 15 questions, each with 4 possible answers via radio inputs.
What I want to do is see if I can use $_POST or $HTTP_POST_VARS totell me which answer (radio input) the viewer has selected for each question.
The code I am using at the moment is:-

if ( $POST ) {
while(list($key, $value) = each($POST)) {
echo "$key = $value <br>";
}
}

but this only displays as follows:-

id_row97 = Array
id_row9 = Array
id_row95 = Array
id_row26 = Array and so on.

Does anyone know if this is possible, and if so, how I might achieve it.
Thanks in advance

[tsinka]

Hi,

do the questions and answer come from a database table ?

Change the names/values of the radio inputs so that you get one array that contains the selected answers. Something like (shortened):

<form>
....
<input type="radio" name="id_row[5]" value="20">Answer 5_1<br>
<input type="radio" name="id_row[5]" value="21">Answer 5_2<br>
<input type="radio" name="id_row[5]" value="22">Answer 5_3<br>
<input type="radio" name="id_row[5]" value="23">Answer 5_4<br>
<input type="radio" name="id_row[9]" value="1">Answer 9_1<br>
<input type="radio" name="id_row[9]" value="2">Answer 9_2<br>
<input type="radio" name="id_row[9]" value="3">Answer 9_3<br>
<input type="radio" name="id_row[9]" value="4">Answer 9_4<br>
...
</form>

In the example above the index used in id_row is the id of the question. The values are the ids of the answers.

After submission of the form you get an array looking like:

// user selected question 5/answer 3 and question 9/answer 3
// the id_row part of the POST array looks like
// $arr = array("id_row" => array("5"=>22,"9"=>3));
$arrAnswers = isset($_POST['id_row']) ? $_POST['id_row'] : array();

foreach($arrAnswers as $key => $value) {
  echo "Question: $key - Answer: $value<br>\n";
}

Thomas

[terrym]

Hi tsinka

Your solution looked the most promising, but sadly it didn't work. So I'll put some of the relevant code here and maybe you can see where I am going wrong...

This is the section where the user sees each question. Each question is randomly selected so we don't know which number it will be.

echo "<tr>";
echo "<td width='100%' colspan='8'>$id - $question</td>"; // Question n
echo "</tr>";

echo "<tr>";
echo "<td width='22%'>$opt1</td>"; // 1st answer for question n
echo "<td width='3%'><input type='radio' name='$option' value=$opt1></td>";

echo "<td width='22%'>$opt2</td>"; // 2nd answer for question n
echo "<td width='3%'><input type='radio' name='$option' value=$opt2></td>";

echo "<td width='22%'>$opt3</td>"; // 3rd answer for question n
echo "<td width='3%'><input type='radio' name='$option' value=$opt3></td>";

echo "<td width='22%'>$opt4</td>"; // 4th answer for question n
echo "<td width='3%'><input type='radio' name='$option' value=$opt4></td>";
echo "</tr>";

Because the question number is not known, the radio name value (which is the same as your example?) is derived as follows:-

while ($row = mysql_fetch_array($display)) {
...... questions and answers
$option = "id_row" . $id . "[option]";
}

Obviously, $option is something like id_row[115] for question number 115.

This bit of code is pretty well at the start of the body, and is actually your suggestion.

if ($_POST[sub_button] == "yes") {

echo "Form Submission! <br>"; // Tests whether code reached.

$arrAnswers = isset($POST['id_row']) ? $POST['id_row'] : array();
foreach($arrAnswers as $key => $value) {
echo "Question: $key - Answer: $value<br>\n";
}
}

When run, your example just displays Form Submission! No errors either.

I hope I've explained things a bit better.
Terry

[tsinka]

With
$option = "id_row" . $id . "[option]";

you get e.g.

id_row115[option]

Try
$option = "id_row[$id]";

instead.

Please post the complete while loop including the "....... questions and answers " part.

Thomas

[terrym]

Hi Thomas

Here is the (almost) complete listing of the offending script. The only things missing are bits of irrelevant HTML. Plus, it looks a bit untidy as all my nice tabs have been decimated.

I hope you understand it, and fingers crossed, that you can see where I have gone wrong.

<html>
<head>
<title>General Knowledge Quiz</title>
</head>
<body>

<div align="center"><h3>General Knowledge Quiz</h3>
<h2>Questions</h2></div>

include "contentdb.php";
global $quiz;

$questions = mysql_query("SELECT * FROM $quiz_table ORDER BY id",$db);
$total_questions = mysql_num_rows($questions);

if ($_POST[sub_button] != "yes"){

// Random number up to max records in Table.

	$x = array(); 
	while ($i < 16){
	    $temp_x = mt_rand(1, $total_questions); 
	    if (!in_array($temp_x, $x)) { 
	        $x[$i++] = $temp_x; 
	    }
	}

// Select each of the 15 records (Questions & answers) according to random numbers above.

	foreach ($x as $key => $current){
		if ($key > 0){
			$display = mysql_query("SELECT * FROM $quiz_table WHERE id = $current",$db);

		echo "<form method='POST' action='quizphp.php'>";
		echo "<table width='96%' border='0' cellspacing='0' cellpadding='3' align='center'>";

		while ($row = mysql_fetch_array($display)) {
			$id 	  = $row["id"];
			$question = $row["question"];
			$opt1 	  = $row["opt1"];
			$opt2 	  = $row["opt2"];
			$opt3 	  = $row["opt3"];
			$opt4 	  = $row["opt4"];
			$answer   = $row["answer"];
			$option   = "id_row" . $id . "[key]";

// Displays the Questions and 4 possible answers for each question.

echo "<tr>";
   echo "<td width='100%' colspan='8'><font style='color:red; font-size:7pt'>$id&nbsp;&nbsp;<font style='color:navy;    font-size:10pt'>$question</font></td>";
echo "</tr>";

echo "<tr>";
   echo "<td width='22%'><font style='color:blue; font-size:11pt'>$opt1</font></td>";
   echo "<td width='3%'><font style='color:red; font-size:7pt'>1</font><input type='radio' name='$option' value=$opt1 checked></td>";

   echo "<td width='22%'><font style='color:blue; font-size:11pt'>$opt2</font></td>";
   echo "<td width='3%'><font style='color:red; font-size:7pt'>2</font><input type='radio' name='$option' value=$opt2></td>";

   echo "<td width='22%'><font style='color:blue; font-size:11pt'>$opt3</font></td>";
   echo "<td width='3%'><font style='color:red; font-size:7pt'>3</font><input type='radio' name='$option' value=$opt3></td>";

   echo "<td width='22%'><font style='color:blue; font-size:11pt'>$opt4</font></td>";
   echo "<td width='3%'><font style='color:red; font-size:7pt'>4</font><input type='radio' name='$option' value=$opt4></td>";
echo "</tr>";
         }
      }
   }

echo "</table>";
echo "<input type='hidden' name='first_time' value='no'>";
echo "<input type='hidden' name='sub_button' value='yes'>";
echo "<input type='hidden' name='x_array' value='" . join('|', $x) . "' >";
echo "<br><center><input type='submit' value='Check your Score' name='submit'></center>";
echo "</form>";
}


else if ($_POST[sub_button] == "yes"){
	$xx = explode('|', $_POST['x_array']);
[code=php]

// Test code only.

echo "<br>Button is pressed!<br>";
foreach ($xx as $key => $current){
	if ($key > 0){
		echo "ID= $key is $current <br>";
	}
}

// Above is CORRECT!
// In the section below, I want to determine which option (1 - 4) the user has clicked for each question. So I can see if the answer is correct?

	foreach ($xx as $key => $current){
		if ($key > 0){
			$display = mysql_query("SELECT * FROM $quiz_table WHERE id = $current",$db);

		while ($row = mysql_fetch_array($display)) {
			$id 	  = $row["id"];
			$question = $row["question"];
			$opt1 	  = $row["opt1"];
			$opt2 	  = $row["opt2"];
			$opt3 	  = $row["opt3"];
			$opt4 	  = $row["opt4"];
			$answer   = $row["answer"];

			$quiz = array(
				'id' => $id,
				'question' => $question,
				'opt1' => $opt1,
				'opt2' => $opt2,
				'opt3' => $opt3,
				'opt4' => $opt4,
				'answer' => $answer);
echo "$quiz[id] - $quiz[question] - $quiz[opt1] - $quiz[opt2] - $quiz[opt3] - $quiz[opt4] - <b>$quiz[answer]</b> <br>";
			}
		}
	}


}

</body>
</html>

Table details (MySQL)

id tinyint(4) PRI
question varchar(255)
opt1 varchar(255)
opt2 varchar(255)
opt3 varchar(255)
opt4 varchar(255)
answer varchar(255)

I've often wondered how that was done?
Terry

[tsinka]

About the "tab" problem:

It is possible to post your code highlighted by doing something like this:

&#091;php]
//some code
$a="b";
&#091;/php]

This will look like:

//some code
$a="b";

Edit your last post and add the php tags.

Thomas

[terrym]

Hi Thomas

Sorry for the delay, but I've been at work for the last 22 hours.

Terry

[tsinka]

You can put the php tags around the complete code including any HTML code. That makes it easier to read the complete code 🙂

Read the following vB code section to get an overview of tags you can use.

About that array problem. Here's a simple example (without any variable checking) showing how you can change the input names to get a multi dimensional array in PHP:

<?PHP
print_r($_POST);
echo "<br>";
foreach($id_row as $key => $value) {
  echo "$key - $value<br>\n";
}
?>
<html>
<head>
</head>
<body>
<form method="post" action="<?=$_SERVER['PHP_SELF']?>">
<input type="radio" name="id_row[9][0]" value="1">Answer 9_1<br>
<input type="radio" name="id_row[9][1]" value="2">Answer 9_2<br>
<input type="radio" name="id_row[9][2]" value="3">Answer 9_3<br>
<input type="radio" name="id_row[9][3]" value="4">Answer 9_4<br>
<input type="radio" name="id_row[8][0]" value="1">Answer 8_1<br>
<input type="radio" name="id_row[8][1]" value="2">Answer 8_2<br>
<input type="radio" name="id_row[8][2]" value="3">Answer 8_3<br>
<input type="radio" name="id_row[8][3]" value="4">Answer 8_4<br>
<input name="submit" type="submit" value="submit">
</form>
</body>
</html>

But I'm not sure if you need a two dimensional array at all. In your code you create an array containing 16 randomly selected ids. So the only value of interest is the question id. Which additional value do you need in the name of the inputs ?

Besides that, I think there might be a way to get the random questions without using the mt_rand rand function. I think you can do that with a modified SQL query.

Edit your post containing the more or less complete code so that the complete code is enclosed by php tags.
Or post the code as file. You can attach e.g. .txt files to a post.

Thomas

[terrym]

Hi Thomas

There isn't any more code. What I am trying to achieve is as follows.

Ultimately, the MySQL Table will hold several hundred questions. Each record will have the Question itself, four possible Answers, and the actual Correct Answer. So Record #1 might look like this:-
Q - What colour is Blue?
A1 - Red - Option 1
A2 - Green - Option 2
A3 - Blue - Option 3
A4 - Yellow - Option 4
CA - Blue - Correct Answer

So, when the fifteen questions are displayed to a user, there will be 15 Questions and 60 Answers shown on the screen.

The user will then select one Answer (from 4) for each of the Questions.

What I would like the script to show me, at this stage at least, might look something like this:-

id Question No User Choice

---

01 - Question 121 Option 3
02 - Question 98 Option 4
03 - Question 78 Option 1
04 - Question 317 Option 3
05 - Question 5 Option 2
06 - Question 99 Option 4
07 - Question 105 Option 1
08 - Question 217 Option 4
09 - Question 56 Option 2
10 - Question 79 Option 4
11 - Question 186 Option 3
12 - Question 256 Option 4
13 - Question 3 Option 1
14 - Question 100 Option 2
15 - Question 73 Option 1

I can then check to see if any of the user's choices match the correct answer for each question.
Obviously, there is quite a bit more than this in the total "application", but for the moment, all I want to do is to know which Option has been selected for each Question.

To me, this looks like a Multi-Array? But maybe there is a better way of doing it?

Regards
Terry

[tsinka]

Find attached a script partly based on your script. I tested it on my server and it worked. I had not much time so it might need some tweaking.

Thomas

[terrym]

Thanks Thomas

I have had a very brief look at it, and I will try and have a good look over the next couple of days. Unfortunately, I'm right in the middle of some really hectic shifts.

I'll get back to you as soon as possible.

Terry

[terrym]

Hi Thomas

I hope you're still out there. I have managed to partially solve the problem, mainly by making the form action a completely new page. This has made the code a lot simpler.

But now I have a slightly different problem. When I select an answer to each of the 15 questions, I'm taken to this new page where the $_POST array is echoed to the screen in a simple foreach loop.

The problem now seems to be when the $_POST array is created in the INPUT fields as I have already shown, it seems to come to a halt whenever it encounters a SPACE character in the answer text.

This is what I get (left column) and what it should be (right column) and the bits missing are in bold. Apart from this little niggle, everything else is fine. I'm hoping that the answer is a simple one.

1 --- A --- A Dopping
2 --- Mecca --- Mecca
3 --- A --- A Sedge
4 --- Robin --- Robin Reliant
5 --- An --- An Army
6 --- By --- By Flooding
7 --- Fifth --- Fifth
8 --- Calvin --- Calvin and Hobbes
9 --- 1931 --- 1931
10 --- 36 --- 36 Years
11 --- A --- A Litter
12 --- Arthur --- Arthur Miller
13 --- A --- A Gaggle
14 --- 18 --- 18 Years
15 --- A --- A Band

Thanks
Terry

[tsinka]

Ok,

in most cases this is caused by missing quotes. Post the codes and check if you have something like

value=A Dopping
instead of
value="A dopping"

Thomas

[terrym]

Hi Thomas

You're quite right. I was using $opt1 and now that I'm using '$opt1', it's OK!

Thanks again (until next time?)
Terry