在php中验证表单

问题描述:

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 ......

我正在尝试验证一种形式的测试。 我在answer.php中收到错误。基本上我想确认每个问题都已得到解答。 p>

表格: strong> p> $ sql1 =“SELECT * FROM ex_question WHERE test_name ='$ tid'ORDER BY q_nr”; $ result1 = mysql_query($ sql1); echo“&lt; form method ='post'name =' form1'action ='answer.php'&gt;“; 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“&lt; P&gt;&lt; strong&gt; $ q_nr $ question&lt; / strong&gt;&lt; BR&gt;”; echo“&lt; BR&gt;”; echo“&lt; / p&gt;”; if($ q_type!='mr'){ if($ option1!=“”){ echo“&lt; input type ='radio'name ='question [$ q_nr]'value ='A'&gt; $ option1&lt; BR&gt;“; } else { echo''; } if($ option2!=“”){ echo“&lt; input type ='radio'name ='question [$ q_nr]'value ='B'&gt; $ option2&lt; BR&gt;”; } else { echo''; } if($ option3!=“”){ echo“&lt; input type ='radio'name ='question [$ q_nr]'value ='C'&gt; $ option3&lt; BR&gt;”; } else { echo''; } } else {//否则如果不是&lt;&gt; mr if($ option1!=“”){ echo“&lt; input type ='checkbox'name ='question [$ q_nr] []'value ='A'&gt; $ option1&lt; BR&gt;”; } else { echo''; } if($ option2!=“”){ echo“&lt; input type ='checkbox'name ='question [$ q_nr] []'value ='B'&gt; $ option2&lt; BR&gt;”; } else { echo''; } if($ option3!=“”){ echo“&lt; input type ='checkbox'name ='question [$ q_nr] []'value ='C'&gt; $ option3&lt; BR&gt;”; } else { echo''; } } //如果q_type&lt;&gt;则结束其他 mr echo“&lt; BR&gt;”; echo“&lt; / p&gt;”; } //结束时row1 echo“&lt; input type ='submit'value ='Submit'name ='提交 '&gt;“; echo”&lt; / form&gt;“; code> pre>

answer.php strong> p>

  foreach($ _ POST ['question'] as $ key =&gt; $ ans){
if($ ans [] =''){
echo“answer is empty”; 
} 
  } 
  code>  pre> 
 
 

我收到错误:警告:为......中的foreach()提供的参数无效 strong> p> div>

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.

One thing is that you are assigning the answer rather than checking it, use ==

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

and instead of using

name='question[$q_nr]'

I would use for the radio fields

name='question_{$q_nr}'

and for the checkboxes

name='question_{$q_nr}[]'

On answer.php you should be able to do a print_r($_POST) to check what you are getting.