Why does this PHP code give "undefined index"?

Question

I have this code:

print_r(array_keys($variables));
if (array_key_exists('form', $variables)) {
 print "YES!";
}
$imgs = $variables['form']['field_images'];

It's a part of the code that I use to theme a form page in Drupal. YES is printed out, however, drupal reports undefined index for that. Thanks for your generous help

Are you sure it's not reporting that field_images is undefined? — Tieson T.
– Tieson T., Commented Jul 30, 2012 at 7:41

Ikke · Accepted Answer · 2012-07-30 07:41:43Z

1

$variables['form'] does exist, but $variables['form']['field_images] probably not. That's why you get the notice about undefined index.

So you should make sure that the subkey also exists before you are calling it.

answered Jul 30, 2012 at 7:41

Ikke

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Comments

Community · Accepted Answer · 2017-05-23 11:55:46Z

0

as an example implemenation of Ikke`s answer:

if ( !array_key_exists('form', $variables) ) {
    echo 'missing parameter form';
}
else if ( !array_key_exists('field_images', $variables['form']) ) {
        echo 'missing parameter field_images';
}
else {
    $imgs = $variables['form']['field_images'];     
}

edited May 23, 2017 at 11:55

CommunityBot

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answered Jul 30, 2012 at 7:43

VolkerK

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Comments

Abid Hussain · Accepted Answer · 2012-07-30 08:14:36Z

0

Try this:-

PHP throws the notice. You can add an isset() or !empty() check to avoid the error, like such:

if(isset($variables)) ) && !empty($variables)) ))
{

    if (array_key_exists('form', $variables)) {
     print "YES!";
    }
    $imgs = $variables['form']['field_images'];

}

answered Jul 30, 2012 at 8:14

Abid Hussain

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