预定义常量

INTL_ICU_VERSION (string): The current ICU library version as a dotted-decimal string.
INTL_MAX_LOCALE_LEN (int): Limit on locale length, set to 80 in PHP code. Locale names longer than this limit will not be accepted.
IDNA_DEFAULT (int): Prohibit processing of unassigned codepoints in the input for IDN functions and do not check if the input conforms to domain name ASCII rules.
IDNA_ALLOW_UNASSIGNED (int): Allow processing of unassigned codepoints in the input for IDN functions.
IDNA_USE_STD3_RULES (int): Check if the input for IDN functions conforms to domain name ASCII rules.
IDNA_CHECK_BIDI (int): Check whether the input conforms to the BiDi rules. Ignored by the IDNA2003 implementation, which always performs this check.
IDNA_CHECK_CONTEXTJ (int): Check whether the input conforms to the CONTEXTJ rules. Ignored by the IDNA2003 implementation, as this check is new in IDNA2008.
IDNA_NONTRANSITIONAL_TO_ASCII (int): Option for nontransitional processing in idn_to_ascii(). Transitional processing is activated by default. This option is ignored by the IDNA2003 implementation.
IDNA_NONTRANSITIONAL_TO_UNICODE (int): Option for nontransitional processing in idn_to_utf8(). Transitional processing is activated by default. This option is ignored by the IDNA2003 implementation.
INTL_IDNA_VARIANT_2003 (int): Use IDNA 2003 algorithm in idn_to_utf8() and idn_to_ascii(). This is the default. This constant and using the default has been deprecated as of PHP 7.2.0.
INTL_IDNA_VARIANT_UTS46 (int): Use UTS #46 algorithm in idn_to_utf8() and idn_to_ascii(). Available as of ICU 4.6.
IDNA_ERROR_EMPTY_LABEL (int)
IDNA_ERROR_LABEL_TOO_LONG (int)
IDNA_ERROR_DOMAIN_NAME_TOO_LONG (int)
IDNA_ERROR_LEADING_HYPHEN (int)
IDNA_ERROR_TRAILING_HYPHEN (int)
IDNA_ERROR_HYPHEN_3_4 (int)
IDNA_ERROR_LEADING_COMBINING_MARK (int)
IDNA_ERROR_DISALLOWED (int)
IDNA_ERROR_PUNYCODE (int)
IDNA_ERROR_LABEL_HAS_DOT (int)
IDNA_ERROR_INVALID_ACE_LABEL (int)
IDNA_ERROR_BIDI (int)
IDNA_ERROR_CONTEXTJ (int): Errors reported in a bitset returned by the UTS #46 algorithm in idn_to_utf8() and idn_to_ascii().

User Contributed Notes

PHP Guru 03-Oct-2020 03:45


idn_to_ascii('fa?.de');



will return fass.de

(Due to Germans using the ? symbol as a contraction of ss)



idn_to_ascii('fa?.de', IDNA_NONTRANSITIONAL_TO_ASCII);



will return xn--fa-hia.de

(This is the correct behavior too allow fa?.de and fass.de to be registered as different domain names.)



idn_to_utf8('xn--fa-hia.de');



will return fass.de



idn_to_utf8('xn--fa-hia.de', IDNA_NONTRANSITIONAL_TO_UNICODE);



will return fa?.de

(Again this is the correct behavior.)