Learn some tips about Drupal 8

 Learning a new system usually means learning about its little quirks. Drupal 8 has its fair share of quirks. Here are some quick tips that I have learned in the past few months working on my first Drupal 8 project. ### addExpression Suppose you need to get the last time an item in a table was edited. You can build a dynamic query and, instead of using fields(), you'd use addExpression() like so: `$query->addExpression('MAX(mod_date)', 'col_alias');` Now you will get the highest timestamp. `$timestamp = $query->execute()->fetchField();` ### Differences between `$entity->field_name` and `$entity->get('field_name')` `$entity->field_name` will return null if the field does not exist while `$entity->get('field_name')` will throw an Exception. Sometimes you'll want one behavior over another so keep that in mind. ### Adding a class to a item list elements I almost went mad looking for an answer until I dived into the code and learned about `#wrapper_attributes`. Just add this to your item list render array and you're good to go. It will apply those attributes to each `

` tag within your item list. ### appendItem If you need to add a value to a multivalue field in an entity, you can use `appendItem()` to get the job done. `$entity->field_multivalue->appendItem($some_other_entity_id);` Over the coming weeks, I or any of my fellow developers here at [Rootstack](http://rootstack.com) will be posting quick tips for other developers new to Drupal 8. I'm sure you will learn a thing or two or, at the very least, we will save you from a mild headache.