$contactTypes = CRM_Core_PseudoConstant::get('CRM_Core_DAO_Contact', 'contact_type');
$activityTypes = CRM_Core_PseudoConstant::get('CRM_Activity_BAO_Activity', 'activity_type_id');
$contributionStatuses = CRM_Core_PseudoConstant::get('CRM_Financial_DAO_FinancialType', 'contribution_status_id');Overall, the CRM_Core_PseudoConstant class is a useful tool for developers working with CiviCRM to retrieve and display various pseudo-constants.