A php include (a form submission) prints this when the form inputs were valid.
if ( $valid ) {
    echo "<script type='text/javascript'>
    $(document).ready(function() {
        console.log('success');
        notificationOutput('success', 'Successfully subscribed');
    });
    </script>";
In my header.php I'm including jQuery.
However when doing the thing above my console tells me that it doesn't know $. It doesn't make a difference if I write jQuery(document).ready(…
What do I miss here? As said above the echo is inside an included file so the header with all its scripts is already on the page.
Thank you in advance.
 
     
     
    