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• http://mayokara.info/note/view/345

javascript:
(function htmlEscape(h){
  h=function(s){
    return s.replace(/[&<>"']/g, function(m){
      return ({
        "&":"&amp;",
        "<":"&lt;",
        ">":"&gt;",
        '"':"&quot;",
        "'":"&#39;"
      })[m];
    });
  };
prompt("output",h(prompt("input","")));
})();

prompt に入力すると改行を落しちゃうねえ。

javascript:
(function htmlEscape(h){
  h=function(s){
    return s;
  };
prompt("output",h(prompt("input","")));
})();

prompt echo