Changing number of values on a field in installation profile

Question

I am creating an installation profile with multiple fields. For a 'file' field I want to change the number of values. I have two questions about this.

Is this an field setting or an instance setting? and what is the right way of changing this setting I tried these:

'number_values' => '2',
'max_value' => '2',
'max_values' => '2',
'values' => '2',
'value' => '2',

I can't find any of this on the internet. Any help and tips would be appreciated.

Answer 1

It's a field setting (cardinality), so assuming you're using field_create_field() to create it...

$field = array(
  'entity_types' => array('node'),
  'cardinality' => 2,
  'translatable' => FALSE,
  'locked' => FALSE,
  // etc...
);
field_create_field($field);

For unlimited values you can use the FIELD_CARDINALITY_UNLIMITED constant.