How to gather data from a checkbox form

[ctmarco3]

Hello all I am working on creating a basic ordering form that allow the user to use check-boxes to select certain products and than return a total back to them.

I am having a hard time figuring out the php code to gather and calculate things. What I dont quite understand is how to pass the data properly so my $sum calculation actually knows what the values are...

 

In my html doc I have my checkboxes as follows:

//formatted in tables

<input type = "checkbox" name = "eight100wattreg" size ="40" /> <input type = "checkbox" name = "four100wattreg" size ="40" /> //etc....

 

and in my php doc:

 

<?php>

//get form values

$four100wattreg = $_POST["four100wattreg"];

$eight100wattreg = $_POST["eight100wattreg"];

$four100wattlong = $_POST["four100wattlong"];

$eight100wattlong = $_POST["eigth100wattlong"];

$payment = $_POST["payment"];

//set lightbulb values

$four100wattreg=2.39;

$eight100wattreg=2.39;

$four100wattlong=2.39;

$eight100wattlong=2.39;

 

//calculate costs

if (isset($_POST['four100wattreg'])

{

//checkbox is checked

$four100wattreg = $_POST['four100wattreg'];

 

}

else

if (!isset($_POST['checkbox'])

{

//checkbox not checked

$four100wattreg = 0; 

}

 

$sum = $four100wattreg + $eight100wattreg + $four100wattlong + $eigth100wattlong;

?>

<?php>

echo "Your total is: '$sum' <br />";

?>

 

I also attached the files if someone wants to look at them in they're entirety. Any advice would be greatly appreciated, but please keep in mind I am a php beginner and am still learning.

Thanks,

Charlie

17386_.txt

17387_.php

[thomasw_lrd]

$four100wattreg=2.39;

 

You're using the same variables for the cost as the checkbox.

 

You should rewrite them as $four100wattregcost. 

 

Also, this line

 

echo "Your total is: '$sum' <br />"

 

Should be

echo "Your total is: ".$sum." <br />"

 

Adding the dots is like concatenating it all into one big string.

[AyKay47]

$four100wattreg=2.39;

 

You're using the same variables for the cost as the checkbox.

 

You should rewrite them as $four100wattregcost.

to explain this post further so you understand why it is not correct, when you set the variable $four100wattreg = $_POST["four100wattreg"]; and then again $four100wattreg=2.39;

you are overwriting the first value that you set $four100wattreg to with the new value (2.39). You should be using unique variable names for each unique value that you want PHP to remember.

 

if (!isset($_POST['checkbox'])
{
//checkbox not checked
$four100wattreg = 0;  
}

 

where is $_POST['checkbox'] being passed to the server?

[Psycho]

Also, this line

 

echo "Your total is: '$sum' <br />"

 

Should be

echo "Your total is: ".$sum." <br />"

 

Adding the dots is like concatenating it all into one big string.

There is nothing wrong with what he has. The variable will be parsed inside the double quoted string.

[ctmarco3]

OK that makes sense, thank you everyone for the replies.

What I don't get than is how to get the value for my variable pushed to my $sum command.

Is there a way to say do something like this perhaps?:  If the box is checked than my  $four100wattreg = 2.39, if the box is unchecked than  $four100wattreg = 0

What would be the best way to handle that?

 

 

$four100wattreg=2.39;

 

You're using the same variables for the cost as the checkbox.

 

You should rewrite them as $four100wattregcost.

to explain this post further so you understand why it is not correct, when you set the variable $four100wattreg = $_POST["four100wattreg"]; and then again $four100wattreg=2.39;

you are overwriting the first value that you set $four100wattreg to with the new value (2.39). You should be using unique variable names for each unique value that you want PHP to remember.

 

if (!isset($_POST['checkbox'])
{
//checkbox not checked
$four100wattreg = 0;  
}

 

where is $_POST['checkbox'] being passed to the server?

[thomasw_lrd]

Yes and no.  Inside you're if statement you are posting the checkbox value. 

 

What you would want to do is something like this.

//calculate costs
if (isset($_POST['four100wattreg'])
{
//checkbox is checked
$four100wattreg = 2.39;

}
else   
if (!isset($_POST['four100wattreg'])
{
//checkbox not checked
$four100wattreg = 0; 
}

 

I believe that is correct, but I could be wrong. I didn't test it.  I'm sure some of the better programmers on here may have a better solution.

[Psycho]

I'm not going to go through and rewrite all your code. But, you should set up your data into an array or database. Then use that for all your processing:

 

A very simple format

$products = array(
    'Four 100 Watt Reg' => 2.39,
    'Eight 100 Watt Reg' => 2.39,
    'Four 100 Watt Long' => 2.39,
    'Four 100 Watt Long' => 2.39,
)

 

Then you can use that data to: create the input fields and process the data.

 

I would create the input fields something like this so they are an array (much easier to process)

foreach($products as $prodName => $price)
{
    echo "<input type='checkbox' name='products[]' value='$prodName'> $prodName<br>\n";
}

 

Then to process the post data into a total

$total = 0;
foreach($_POST['products'] as $prodName)
{
    $total += $products[$prodName];
}

[vivekanand25]

use this pages to see the display in ur page

17388_.php

17389_.php

[ctmarco3]

I'm not going to go through and rewrite all your code. But, you should set up your data into an array or database. Then use that for all your processing:

 

A very simple format

$products = array(
    'Four 100 Watt Reg' => 2.39,
    'Eight 100 Watt Reg' => 2.39,
    'Four 100 Watt Long' => 2.39,
    'Four 100 Watt Long' => 2.39,
)

 

Then you can use that data to: create the input fields and process the data.

 

I would create the input fields something like this so they are an array (much easier to process)

foreach($products as $prodName => $price)
{
    echo "<input type='checkbox' name='products[]' value='$prodName'> $prodName<br>\n";
}

 

Then to process the post data into a total

$total = 0;
foreach($_POST['products'] as $prodName)
{
    $total += $products[$prodName];
}

I wondered about using array from the research I had done but wasn't quite sure how to implement it, let me do some additional research and see if I can take your advice and actually integrate it into my form.

Thanks so much! I may be back, but hopefully not.