Detecting Kanji, Hiragana, and/or Katakana with Javascript

 

2009-04-30 . Category: Code . Tags: Japanese, Kanji, Hiragana, Katakana, JavaScript, input validation, utf-8, unicode

Does your web application need to validate Japanese input; need to determine if a String is kanji, hiragana, katakana, or a mixture?

Here's how...

 
// matches a single kanji character
String.prototype.isaKanji = function(){
  return !!this.match(/^[\u4E00-\u9FAF]$/);
}

// matches one or more kanji characters
String.prototype.isKanji = function(){
  return !!this.match(/^[\u4E00-\u9FAF]+$/);
}

// matches one or more hiragana characters
String.prototype.isHiragana = function(){
  return !!this.match(/^[\u3040-\u3096]+$/)
}

// matches one or more full-width katakana characters
String.prototype.isKatakana = function(){
  return !!this.match(/^[\u30A1-\u30FA]+$/)
}

// kana is hirgana, full-width katakana, 
// half-width katakana, or a katakana 
// phonetic extension
String.prototype.isKana = function(){
  return !!this.match(/^[\u3040-\u3096|\u30A1-\u30FA|\uFF66-\uFF9D|\u31F0-\u31FF]+$/)
}

// matches a String that contains kanji and/or kana character(s)
String.prototype.isKanjiKana = function(){
  return !!this.match(/^[\u4E00-\u9FAF|\u3040-\u3096|\u30A1-\u30FA|\uFF66-\uFF9D|\u31F0-\u31FF]+$/);
}

All of the methods return either true, or false. Punctuation marks will not match. You also need to be sure to set the charset of the page to utf-8.

 
//returns true 
"漢字".isKanji();

//returns false 
"漢字".isaKanji();

//returns true 
"字".isaKanji();

// returns true
"カタカナ".isKatakana();

// returns true
"ひらがな".isHiragana();

// returns true
"漢字ひらがなカタカナ".isKanjiKana();

// returns false
"漢字ひらがなカタカナRomaji".isKanjiKana();

// returns false
"漢字ひらがなカタカナ。。。".isKanjiKana();