concatenation in laravel controller goes wrong

$data = <div class="">
    <h3><a class="text-dark" href=" url("/notice_details/'.$n->id.'")">'.$n->title.'</a>**</h3>

    <p class="text-muted"><i class="mdi mdi-calendar m-r-5"></i>Posted on :'.$n->date.'</p>

    <p class="font-13 text-muted m-b-0">
         '.$string.'
    </p>
</div>   

this is the code in my controller(laravel project 5.5) want to generate the url in view like localhost/learning/notice_details/1 in my project url() returns localhost/learning but i m unable to genrate the right href link may something wrong with concatenation or .... ??

via Chebli Mohamed