CODEWITHSUNDEEP
php
user3173207
user3173207

Reputation: 289

PHP Define index for HTML form $_POST

I have the following php code 

<?php
    if(isset($_POST['address_building_number']) OR !isset($_POST['address_building_number'])){
        $address_building_number = $_POST['address_building_number'];
        echo 'Hello';
        $good = 'Good bye';
    }
    echo $address_building_number;
    echo $good;

?>

When I hit the submit button the words Hello and Good bye are displayed but it is telling me PHP Notice: Undefined index: Now $_POST['address_building_number' is from an HTML input form with a name address_building_number.

How can I modify if(isset($_POST['address_building_number']) OR !isset($_POST['address_building_number'])){ so that I can 'define the index' while be still able to echo Hello and Good bye.

Upvotes: 0

Views: 1627

Answers (2)

Funk Forty Niner
Funk Forty Niner

Reputation: 74220

Edit

All-in-one version

<?php
    if(isset($_POST['address_building_number']) || !empty($_POST['address_building_number'])){
        $address_building_number = $_POST['address_building_number'];
        echo 'Hello';
        $good = 'Good bye';
    }
    echo $address_building_number;
    echo $good;

    // comment out exit; if you want the form to NOT appear after submit
    // exit;
?>

<form action="" method="post">
   Name: <input type="text" name="address_building_number"><br>
   <input type="submit" value="Submit">
</form>

Original answer

Your conditionals seem to be fighting against themselves.

Notice the if(isset and if(!isset for the $_POST['address_building_number']

What is happening here is, "if it IS set and if it is NOT set"; being a contradictory statement.

What you probably meant to use was:

if(isset($_POST['address_building_number']) OR !empty($_POST['address_building_number']))

(Quick FYI) If that's the case, || has precedence over OR therefore use:

if(isset($_POST['address_building_number']) || !empty($_POST['address_building_number']))

...which checks to see if it is set, and if it is not empty.

The following has been successfully tested and echo'ed everything with no error messages:

HTML

<form action="action.php" method="post">
   Name: <input type="text" name="address_building_number"><br>
   <input type="submit" value="Submit">
</form>

PHP (action.php) for example

<?php
    if(isset($_POST['address_building_number']) || !empty($_POST['address_building_number'])){
        $address_building_number = $_POST['address_building_number'];
        echo 'Hello';
        $good = 'Good bye';
    }
    echo $address_building_number;
    echo $good;
?>

In regards to "so that I can 'define the index' while be still able to echo Hello and Good bye" - I'm having a hard time understanding what you mean by this.

If what you mean by this is, "if you can still echo "Hello and Good bye" outside of that conditional statement", then the answer is yes; which is just what my answer does, since it's using the OR (||) operator. Had it been the AND (&&) operator, then that would not be possible.

Upvotes: 3

Abhishek Salian
Abhishek Salian

Reputation: 934

1st - your if statement is wrong it always results in true. I am not sure what you trying to do here?

2nd - PHP Notice: Undefined index is shown because your if statement is always true even if you have submitted form or not.

3rd - maybe change if loop to 

if(isset($_POST['submit'])) {

Also make sure submit button has name="submit"

Upvotes: 0

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