.. highlightlang:: us

.. _error_create:

error_create
============

.. index:: error_create

.. us.tag  error_create NOTREADYENGLISH New410

:ref:`error_create` creates an error object.

.. function::  e = error_create(domain, code, message)

.. us.return

**Return Value**

*e* is an error object.

.. us.params

**Parameters**

.. uparam:: domain

   *domain* is the group the error belongs to e.g. "file-error".

.. uparam:: code

   *code* is the error number. The error number is only valid within a group.

.. uparam:: message

   *message* is the error message (string).

.. us.comment

**Comment**

The 3 variables of the error object can be accessed using period (.) - the object 
member-selection expression e.g. ``e.message = "file not found";``. 

.. us.example

**Example**

::

   def test()
   {
       o = obj_create();
       e = o.load("d:/laksjdlksajd");
       if (type(e) == "error") {
           MessageBoxError("%s\n\nError-No.: %d\n%s", e.domain, e.code, e.message);
           return e;
       }
       return 0;
   }

Use of :ref:`error_create` in a UniScript function:

::

   def test(a, b)
   {
       if (argsin() != 2) {
           return error_create("test-error", 1, "no of args must be 2");
       }
       return a+b;
   }

The user of test() can use the return value to check if an error occurred:

::

   res = test(1);
   if (type(res) == "error") {
       MessageBox(res.message);
       ...
   }
   ...

.. seealso::
   :ref:`overview-programming`,
   :ref:`type`

:sub:`id-1376826`