How to write if condition in html statement inside controller in laravel

I want to write if condition inside the controller. i have a HTML statement inside the controller. i want to set require equal to true if only $required variable is set.

    $required = false;

      $a = '<div class="col-md-12" style="margin-top: 20px;"><label>
      </label></div><div class="col-md-8"><select required =   
     "'.$required.'" class="form-control" if($required == true) 
     {multiple=" '.$multiple.' "}></select></div>';

via Chebli Mohamed