index undefined php with $_POST

Question

I am trying to get rid of the index undefined. Every time I click submit without ticking the box, I get an undefined index error.

<html>
    <head>
        <title>Order</Title>
            <style>
            </style>
        <body>
            <form action = "order.php" method = "post">
                Coffee:<p>
                <input type = "checkbox" value = "coffee" name = "cappuccino"/>Capuccino<br>
</form>
        </body> 
    </head>
</Html>

<?php
    $capuccino = 3.75;
    if(isset($_POST["submit"]))
    {
        if($_POST['cappuccino'] <> 'coffee')
        {
            $capuccino = 0;
        }
    }
?>

use isset on all input validations maybe?

Daryl Gill
– Daryl Gill

2013-08-31 09:50:26 +00:00
Commented Aug 31, 2013 at 9:50 — Daryl Gill
– Daryl Gill, Commented Aug 31, 2013 at 9:50

GautamD31 · Accepted Answer · 2013-08-31 09:51:47Z

1

Try with isset like

<?php
    if(isset($_POST["submit"]))
    {
        if(isset($_POST['cappuccino']) && $_POST['cappuccino'] <> 'coffee')
        {
            $capuccino = 0;
        }
    }
?>

You can also use != instead <>

$_POST['cappuccino'] != 'coffee'

answered Aug 31, 2013 at 9:51

GautamD31

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1 Comment

GautamD31 Over a year ago

And tell me the reason who down this

Paul · Accepted Answer · 2013-08-31 09:52:52Z

1

In HTML forms, a value does not get posted if you do not check it. You should test if it was posted first, so your php code would be something like:

<?php
if(isset($_POST["submit"]))
{
    if(isset($_POST['cappuccino']) && $_POST['cappuccino'] <> 'coffee')
    {
        $capuccino = 0;
    }
}
?>

answered Aug 31, 2013 at 9:52

Paul

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Comments

William Buttlicker · Accepted Answer · 2013-08-31 09:53:14Z

0

You condition should be:

if(array_key_exists('cappuccino', $_POST) && isset($_POST['cappuccino']) && $_POST['cappuccino'] <> 'coffee')

answered Aug 31, 2013 at 9:53

William Buttlicker

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Comments

user2727841 · Accepted Answer · 2013-08-31 09:53:42Z

0

    <html>
    <head>
        <title>Order</Title>
            <style>
            </style>
        <body>
            <form action = "order.php" method = "post">
                Coffee:<p>
                <input type = "checkbox" value = "coffee" name = "cappuccino"/>Capuccino<br>
<input type="submit" name="submit" value="Submit" />
</form>
        </body> 
    </head>
</Html>

<?php
    $capuccino = 3.75;
    if(isset($_POST["submit"]))
    {
        if(isset($_POST['cappuccino']) && !empty($_POST['cappuccino']) <> 'coffee')
        {
            $capuccino = 0;
        }
    }
?>

answered Aug 31, 2013 at 9:53

user2727841

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