sitelink1 https://zetawiki.com/wiki/UTF-8_%ED%95%9...%ED%8A%B8) 
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sitelink4  
extra_vars4  
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<script>
function cho_hangul(str) {
  cho = ["ㄱ","ㄲ","ㄴ","ㄷ","ㄸ","ㄹ","ㅁ","ㅂ","ㅃ","ㅅ","ㅆ","ㅇ","ㅈ","ㅉ","ㅊ","ㅋ","ㅌ","ㅍ","ㅎ"];
  result = "";
  for(i=0;i<str.length;i++) {
    code = str.charCodeAt(i)-44032;
    if(code>-1 && code<11172) result += cho[Math.floor(code/588)];
  }
  return result;
}
alert(cho_hangul("안녕하세요"));
// ㅇㄴㅎㅅㅇ
</script>