平仮名を片仮名に変換

const hiraganaToKatakana = (str) => {
  return str.replace(/[\u3041-\u3096]/g, (match) => {
    const chr = match.charCodeAt(0) + 0x60;
    return String.fromCharCode(chr);
  });
};

平仮名のみか判定

const isHiragana = (str) => {
  const regexp = /^[\u{3000}-\u{301C}\u{3041}-\u{3093}\u{309B}-\u{309E}]+$/mu;
  return regexp.test(str);
};

片仮名のみか判定


const isKatakana = (str) => {
  const regexp = /^[\u{3000}-\u{301C}\u{30A1}-\u{30F6}\u{30FB}-\u{30FE}]+$/mu;
  return regexp.test(str);
};