Change record status: 
Project: 
Introduced in branch: 
8.x
Description: 

To check whether a field has data in it, in D7:

<?php
$has_data
= field_has_data($field);
?>

In D8:
<?php
$has_data
= $field->hasData();
?>
Updates Done (doc team, etc.)
Online documentation: 
Not done
Theming guide: 
Not done
Module developer documentation: 
Not done
Examples project: 
Not done
Coder Review: 
Not done
Coder Upgrade: 
Not done
Other: 
Other updates done