toHankakuNumericAndAlphabet method

String toHankakuNumericAndAlphabet()

Converts alphabets and numbers to half-width characters.

アルファベットと数字を半角に変換します。

final text = "ａｂｃｄ";
final converted = text.toHankakuNumericAndAlphabet(); // "abcd"

Implementation

String toHankakuNumericAndAlphabet() {
  final regex = RegExp(r'^[Ａ-Ｚａ-ｚ０-９]+$');
  final string = runes.map<String>((rune) {
    final char = String.fromCharCode(rune);
    return regex.hasMatch(char) ? String.fromCharCode(rune - 65248) : char;
  });
  return string.join();
}