I heard a while back that `isset` is quicker `than array_key_exists`.
Its also more compact - but how can it lead to false results?

On Thu, Apr 18, 2013 at 05:57:49AM -0700, Nikola Petkanski wrote:
>    In DependencyInjection/SymfonyCmfBlogExtension.php:
> 
>  >          $config['class'] = array_merge(array(
>  >              'blog_admin' => 'Symfony\Cmf\Bundle\BlogBundle\Admin\BlogAdmin',
>  >              'post_admin' => 'Symfony\Cmf\Bundle\BlogBundle\Admin\PostAdmin',
>  >              'blog' => 'Symfony\Cmf\Bundle\BlogBundle\Document\Blog',
>  >              'post' => 'Symfony\Cmf\Bundle\BlogBundle\Document\Post',
>  > -        ), $config['class']);
> 
>    What's the benefit of using isset()?
> 
>    I don't see benefit in using either one of these, but using isset() can
>    lead to false results if the intention is to check whether a given index
>    exists.
> 
>    —
>    Reply to this email directly or [1]view it on GitHub.
> 
> References
> 
>    Visible links
>    1. https://github.com/symfony-cmf/BlogBundle/pull/16/files#r3852663