(PHP 5 >= 5.5.0, PHP 7, PHP 8, PECL >= 3.0.0a1)
$reason
,$source
,$codePoint
,&$error
$reason
,$source
,$codeUnits
,&$error
$str
,$toEncoding
,$fromEncoding
,$options
= null
UConverter::REASON_UNASSIGNED
UConverter::REASON_ILLEGAL
UConverter::REASON_IRREGULAR
UConverter::REASON_RESET
UConverter::REASON_CLOSE
UConverter::REASON_CLONE
UConverter::UNSUPPORTED_CONVERTER
UConverter::SBCS
UConverter::DBCS
UConverter::MBCS
UConverter::LATIN_1
UConverter::UTF8
UConverter::UTF16_BigEndian
UConverter::UTF16_LittleEndian
UConverter::UTF32_BigEndian
UConverter::UTF32_LittleEndian
UConverter::EBCDIC_STATEFUL
UConverter::ISO_2022
UConverter::LMBCS_1
UConverter::LMBCS_2
UConverter::LMBCS_3
UConverter::LMBCS_4
UConverter::LMBCS_5
UConverter::LMBCS_6
UConverter::LMBCS_8
UConverter::LMBCS_11
UConverter::LMBCS_16
UConverter::LMBCS_17
UConverter::LMBCS_18
UConverter::LMBCS_19
UConverter::LMBCS_LAST
UConverter::HZ
UConverter::SCSU
UConverter::ISCII
UConverter::US_ASCII
UConverter::UTF7
UConverter::BOCU1
UConverter::UTF16
UConverter::UTF32
UConverter::CESU8
UConverter::IMAP_MAILBOX