When using Laravel blade how do you check if a @yield Is empty?

Try using:

View::yieldContent('named_section')

How does it work?

@if(View::yieldContent('named_section') !== "")
     @yield('named_section')
@else
     Display my default content.
@endif

If needed, you can use php functions together with yieldContent. Try passing yieldContent as a parameter to trim().

@if(trim(View::yieldContent('named_section')) !== "")
     @yield('named_section')
@else
     Display my default content.
@endif