Liquid sandbox

Liquid

<h4>Best way, using links.size check on menu</h4>
{% for link in menus.some-menu.links %}
  {% assign child_link_handle = link.title | handle %}
  {% if menus[child_link_handle].links.size > 0 %}
    {{ link.title }}<br>
    ...expecting menu with links in it...<br>
    {% for childlink in menus[child_link_handle].links %}
      — {{ childlink.title | link_to: childlink.url }}<br>
    {% endfor %}
  {% endif %}  
{% endfor %}

<h4>Good enough way, using == blank check on menu links</h4>
{% for link in menus.some-menu.links %}
  {% assign child_link_handle = link.title | handle %}
  {% if menus[child_link_handle].links != blank %}
    {{ link.title }}<br>
    ...expecting menu with links in it...<br>
    {% for childlink in menus[child_link_handle].links %}
      — {{ childlink.title | link_to: childlink.url }}<br>
    {% endfor %}
  {% endif %}
{% endfor %}

<h4>Bad way, not using == blank on links, nor links.size</h4>
{% for link in menus.some-menu.links %}
  {% assign child_link_handle = link.title | handle %}
  {% if menus[child_link_handle] != blank %}
    {{ link.title }}<br>
    ...expecting menu with links in it...<br>
    {% for childlink in menus[child_link_handle].links %}
      — {{ childlink.title | link_to: childlink.url }}<br>
    {% endfor %}
  {% endif %}  
{% endfor %}

Output

Best way, using links.size check on menu

Submenu 1
...expecting menu with links in it...
— Link 1
— Link 2
— Link 3

Good enough way, using == blank check on menu links

Submenu 1
...expecting menu with links in it...
— Link 1
— Link 2
— Link 3

Bad way, not using == blank on links, nor links.size

Submenu 1
...expecting menu with links in it...
— Link 1
— Link 2
— Link 3
Submenu 2
...expecting menu with links in it...