function ppull($list, $property, $key_property)

libphutil Technical Documentation (Core Utilities)

Access a property on a list of objects. Short for "property pull", this function works just like mpull(), except that it accesses object properties instead of methods. This function simplifies a common type of mapping operation:

$names = array();
foreach ($objects as $key => $object) {
  $names[$key] = $object->name;
}

You can express this more concisely with ppull():

$names = ppull($objects, 'name');

ppull() takes a third argument, which allows you to do the same but for the array's keys:

$names = array();
foreach ($objects as $object) {
  $names[$object->id] = $object->name;
}

This is the ppull version():

$names = ppull($objects, 'name', 'id');

If you pass null as the second argument, the objects will be preserved:

$id_map = array();
foreach ($objects as $object) {
  $id_map[$object->id] = $object;
}

With ppull():

$id_map = ppull($objects, null, 'id');

See also mpull(), which works similarly but calls object methods instead of accessing object properties.