String interpolation in laravel

I tried all of this but can't predict interpolation read all points in official documentation but not yet found elegant solution-

{{ url('/posts/' . $post->id . '/comments' }}

{{ url('/posts/$post->id/comments') }}

Finally this one worked but I expecting something elegant than this

@php
  $url = url('/posts/' . $post->id. '/comments');
@endphp

{{ $url }}