(PHP 7)
IntlChar::foldCase — Perform case folding on a code point
$codepoint
[, int $options = IntlChar::FOLD_CASE_DEFAULT
] )The given character is mapped to its case folding equivalent; if the character has no case folding equivalent, the character itself is returned.
codepointコードポイントを表す integer 型の値 (例: U+2603 SNOWMAN を表す 0x2603)、あるいは UTF-8 文字列としてエンコードされた文字 (例: "\u{2603}")。
options
Either IntlChar::FOLD_CASE_DEFAULT (default)
or IntlChar::FOLD_CASE_EXCLUDE_SPECIAL_I.
Returns the Simple_Case_Folding of the code point, if any; otherwise the code point itself.