How to use regular expressions to highlight JavaScript code

/(\/\/.*|\/\*[\S\s]+?\*\/)|((["'])(?:\\.|[^\\\n])*?\3)|\b(break|continue|do|for|in|function|if|else|return|switch|this|throw|try|catch|finally|var|while|with|case|new|typeof|instance|delete|void)\b|\b(Object|Array|String|Number|Boolean|Function|RegExp|Date|Math|window|document|navigator|location)\b|\b(true|false)\b|\b(null|undefined|NaN)\b|(?:[^\W\d]|\$)[\$\w]*|(0[xX][0-9a-fA-F]+|\d+(?:\.\d+)?(?:[eE]\d+)?)|(?:[^\)\]\}]|^)(\/(?!\*)(?:\\.|[^\\\/\n])+?\/[gim]*)|[\S\s]/g

<style>body {font:14px/18px Consolas;}</style><script id="code">//读入当前代码var code=document.getElementById("code").innerHTML;//修正换行的浏览器差异，去掉头尾的换行和空格code=code.replace(/\r\n|[\r\n]/g,"\n").replace(/^\s+|\s+$/g,"");//开始主匹配code=code.replace(/(\/\/.*|\/\*[.\s]+?\*\/)|((["&#39;])(?:\\.|[^\\\n])*?\3)|\b(break|continue|do|for|in|function|if|else|return|switch|this|throw|try|catch|finally|var|while|with|case|new|typeof|instance|delete|void)\b|\b(Object|Array|String|Number|Boolean|Function|RegExp|Date|Math|window|document|navigator|location)\b|\b(true|false)\b|\b(null|undefined|NaN)\b|(?:[^\W\d]|\$)[\$\w]*|(0[xX][0-9a-fA-F]+|\d+(?:\.\d+)?(?:[eE]\d+)?)|(?:[^\)\]\}]|^)(\/(?!\*)(?:\\.|[^\\\/\n])+?\/[gim]*)|[.\s]/g,function(){  var a,l,i,s;  a=arguments;  //循环匹配到的位置  for(i=1;i<=9;i++)if(s=a[i]){    s=htmlEncode(s);    //每个获取匹配的位置都着上不同的颜色    switch(i){      case 1://注释      return s.fontcolor("#998877").italics();      case 2:case 3://字符串      return s.fontcolor("#AA5544");      case 4://关键词      return s.fontcolor("#333388");      case 5://内置对象      return s.fontcolor("#5555AA");      case 6://布尔值      return s.fontcolor("#DD6600");      case 7://空值      return s.fontcolor("#BB4433");      case 8://数字      return s.fontcolor("#CC3322");      case 9://正则表达式      //这个比较特殊，匹配到的和获取的有些不同      //匹配的时候，前面有个非获取匹配，所以我们要保留非获取匹配的部分      return htmlEncode(a[0]).replace(s,s.fontcolor("#33AA33"));    };  };  //没有获取匹配就直接转义输出  return htmlEncode(a[0]);});
//输出结果document.write(code);
//HTML的转义函数function htmlEncode(e){  var i,s;  for(i in s={    "&":/&/g,""":/"/g,"&#39;":/&#39;/g,    "<":/</g,">":/>/g,"<br/>":/\n/g,    " ":/ /g,"  ":/\t/g  })e=e.replace(s[i],i);  return e;};</script>