The behaviour of these functions is affected by settings in php.ini.
| Name | Default | Changeable | Changelog | 
|---|---|---|---|
| intl.default_locale | PHP_INI_ALL | ||
| intl.error_level | 0 | PHP_INI_ALL | |
| intl.use_exceptions | 0 | PHP_INI_ALL | Available since PHP 5.5 and PECL 3.0.0a1 | 
Here's a short explanation of the configuration directives.
intl.default_locale
      string
     The locale that will be used in intl functions when none is specified (either by omitting the corresponding argument or by passing NULL). These are ICU locales, not system locales. The built-in ICU locales and their data can be explored at » http://demo.icu-project.org/icu-bin/locexp.
The default value is empty, which forces the usage of ICU's default locale. Once set, the ini setting cannot be reset to this default value. It is not recommended that this default be relied on, as its effective value depends on the server's environment.
intl.error_level
      integer
     
       The level of the error messages generated when an error occurs in ICU
       functions. This is a PHP error level, such as
       E_WARNING. It can be set to 0
       in order to inhibit the messages. This does not affect the return values
       indicating error or the values returned by
       intl_get_error_code() or by the class specific
       methods for retrieving error codes and messages.
       Choosing E_ERROR will terminate the script whenever
       an error condition is found on intl classes.
      
The default value is 0.
intl.use_exceptions
      integer
     If set to true, an exception will be raised whenever an error occurs in an intl function. The exception will be of type IntlException. This is possibly in addition to the error message generated due to intl.error_level.
The default value is FALSE.