Undefined Index Error

[SalientAnimal]

Hi All,

 

Can anyone tell me why I am getting an undefined index error message when submitting my form?

 

This is happening only when the tick boxes are not selected, everything is working fine and the information is written to the database as required.

 

Thanks,

 

 

Here is my checkbox code:

 

 <table width="100%" border="0" align="center">
 <tr>
   <td align="right" width="40%"><strong>Additional Visit Reasons :</strong></td>
   <td width="10%"><input type="checkbox" name="accessory" value="Accessory">Accessory</td>
   <td width="10%"><input type="checkbox" name="airtime" value="Airtime">Airtime</td>
   <td width="40%"><input type="checkbox" name="handset" value="Handset">Handset</td>
 </tr>

 </table>

[White_Lily]

Its because the boxes are returning a false (or empty or 0) value.

 

Its the same as an undefined variable, it's because that variable is not storing any data.

[SalientAnimal]

How do I fix it?

 

I can always rely on a reply from you

[Beeeeney]

How do I fix it?

 

I can always rely on a reply from you

 

Use an if statement to make it return a NULL value when nothing is selected.

[SalientAnimal]

Ok so I tried using it like this:

 

if(isset($_POST['accessory'])
}
$_POST['accessory'] == 'Accessory')
else
{
$_POST['N/A']
};

 

But get this error:

Parse error: syntax error, unexpected '}' (T_VARIABLE) in submit_store.php on line 14

[MDCode]

if(isset($_POST['accessory']))
{
$_POST['accessory'] = "Accessory";
} else
{
// Not sure what you're trying to accomplish here
$_POST['N/A'];
}

Edited October 24, 2012 by ExtremeGaming

[SalientAnimal]

Currently when I submit my form I get an undefined index error message. What I am trying to do is to prevent this message from coming up.

 

The error message occurs when the user has't checked the checkboxes.

[MDCode]

 $_POST['N/A']; 

is your problem because it is undefined. If you are trying to mark it as N/A use

 $_POST['accessory'] = "N/A"; 

Edited October 24, 2012 by ExtremeGaming

[SalientAnimal]

I never had that part of the code in my script at all.

 

It was suggested that I add

if(isset($_POST['accessory'])}$_POST['accessory'] == 'Accessory')else{$_POST['N/A']};

 

This is the original submit page:

 

<?php
$con = mysql_connect("localhost","user","password");
if (!$con)
 {
 die('Could not connect: ' . mysql_error());
 }
mysql_select_db("store", $con);

$sql="INSERT INTO store_traffic
(username
, gender
, ethnic_group
, age_group
, requirement
, visit_detail
, accessory
, airtime
, handset
, postpaid
, prepaid
, handset_make)

VALUES
('$_POST[username]'
,'$_POST[gender]'
,'$_POST[ethnic_group]'
,'$_POST[age_group]'
,'$_POST[requirement]'
,'$_POST[visit_detail]'
,'$_POST[accessory]'
,'$_POST[airtime]'
,'$_POST[handset]'
,'$_POST[postpaid]'
,'$_POST[prepaid]'
,'$_POST[handset_make]'
)";


if (!mysql_query($sql,$con))
 {
 die('Error: ' . mysql_error());
 }
echo "<b><font color='white' face='segoe' size='2'>1 record added</b></font>";
include "redirect_store.html";
mysql_close($con)
?>

[PFMaBiSmAd]

The undefined index error message is because form checkboxes (and radio buttons) are only submitted when they are checked. The solution is to have some validation logic in your code to test if a checkbox is set or not and take an appropriate action.

 

if(isset($_POST['accessory'])){
// code for when this checkbox is checked

} else {
// code for when this checkbox is not checked

}

 

Since I don't have the slightest idea what value you want to use when a checkbox is not set, the actual coding in this example is left up to you.

 

P.S. you need to have validation logic for ALL your form inputs and you need to escape string data and cast numerical data to the appropriate numerical data type before putting it into your query statement to prevent sql errors if the data contains sql special characters or to prevent sql injection.

Edited October 24, 2012 by PFMaBiSmAd

[SalientAnimal]

Thanks, I think I was appling the if(isset incorrectly.

 

So just to be sure, I would prefer to leave it blank if the checkbox is not set can I have it as follows:

 

if(isset($_POST['accessory'])){
//code for when this checkbox is checked

}else{
($_POST[''])
// code for when this checkbox is not checked

 

Then, lastly, where in my submit for do I put this part of code?

Edited October 24, 2012 by SalientAnimal

[SalientAnimal]

Managed to solve this with a very basic change on my form rather than the submit part of the page.

 

I just did this:

 

<!-- INCLUDED A HIDDEN FIELD TO SET THE DEFAULT FORM VALUE OF THE CHECKBOX TO "EMPTY" -->
<input type="hidden" name="handset" value="">
<input type="checkbox" name="handset" value="Handset">Handset

Edited October 24, 2012 by SalientAnimal

[White_Lily]

lol - um if you want to leave it blank do something like:

 

if(isset($_POST["accessory"])){

//code for if it IS set

}elseif(!isset($_POST["accessory"])){

//code ofr when it is NOT set

}

[MDCode]

Using any kind of hidden field is a very bad idea (ie Javascript injection)

[SalientAnimal]

It was the only solution I could get to work for what I needed to do.

[MDCode]

lol - um if you want to leave it blank do something like:

 

if(isset($_POST["accessory"])){

//code for if it IS set

}elseif(!isset($_POST["accessory"])){

//code ofr when it is NOT set

}

 

As lily's suggestion states, it is easier and more secure to do this. As far as I see there is no reason why you shouldn't want to do this

[Christian F.]

No real need for that last IF test though: Either it's set or it's not.

 

if (!isset ($_POST['accessory'])) {
   // Error condition, handle it.
   // Let's say it's a fatal one, just to showcase exiting early. 
   return false;
}

// Normal operation, as it is set.

Helps to cut down a lot of the nesting if you utilize the principle of exiting early, and that can have quite a bit impact on the readability. The easier the script is to read, the easier it is to maintain. Especially for others, like those of us trying to help.