在php中验证表单

Question

I'm trying to validate a form of a test. I get an error in answer.php Basically I want to validate that each question has been answered.

The form:

$sql1="SELECT * FROM ex_question WHERE test_name = '$tid' ORDER BY q_nr";
$result1=mysql_query($sql1);
echo "<form method='post' name='form1' action='answer.php'>";
while($row1 = mysql_fetch_array($result1))
{
    $q_nr=$row1['q_nr'];
    $q_type=$row1['q_type'];
    $question=$row1['question'];
    $option1=$row1['option1'];
    $option2=$row1['option2'];
    $option3=$row1['option3'];
echo "<P><strong>$q_nr $question</strong><BR>";
echo "<BR>";
echo "</p>";
if ($q_type != 'mr') {
if($option1!="") {
echo "<input type='radio' name='question[$q_nr]' value='A'>$option1<BR>";
} else {
echo ''; }
if($option2!="") {
echo "<input type='radio' name='question[$q_nr]' value='B'>$option2<BR>";
} else {
echo ''; }
if($option3!="") {
echo "<input type='radio' name='question[$q_nr]' value='C'>$option3<BR>";
} else {
echo ''; }
} else { // else if not <> mr
if($option1!="") {
echo "<input type='checkbox' name='question[$q_nr][]' value='A'>$option1<BR>";
} else {
echo ''; } 
if($option2!="") {
echo "<input type='checkbox' name='question[$q_nr][]' value='B'>$option2<BR>";
} else {
echo ''; } 
if($option3!="") {
echo "<input type='checkbox' name='question[$q_nr][]' value='C'>$option3<BR>";
} else {
echo ''; } 
} //end else if q_type <> mr
    echo "<BR>";
    echo "</p>";
} //end while row1
echo "<input type='submit' value='Submit' name='Submit'>";
echo "</form>";

answer.php

foreach($_POST['question'] as $key => $ans) {
if ($ans[] = '') {
echo "answer is empty";
}
}

I get the error: Warning: Invalid argument supplied for foreach() in ......

Answer 1

This is probably because your $_POST['question'] is empty. This is what happens when you try to do this with an empty array.

Whereas your HTML says: name='question[$q_nr]'.

Print the values in the array to see what it contains, use print_r.

Edit: $_POST['question'] IS NOT an array! While $_POST IS an array...

Maybe you should try to do something like this: foreach ($_POST as $key => $value)

Or do it however you want the result to be displayed.