JS和CSS的问题

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<style type="text/css">
         @import"dy.css";
         @import"hide.css";
</style><script type="text/javascript" src="DOMhelp.js"></script>
<script type="text/javascript" src="sc.js"></script>
</head><body>
<h3>contact details</h3>
<address>aaaaaaa<br/>
         bbbbbb<br/>
cccccc<br/>
dddddd<br/>
</address></body>
</html>
.hide{ position:absolute;
       top:0;
   left:-9999px;
   height:0;
   }
dy.css/* CSS Document */
*{
    margin:0;
padding:0;
}
body{
         font-family:Arial, Helvetica, sans-serif;
font-size:small;
padding:2em;
}
/* js disabled*/
address{
          background:#ddd;
  border:1px solid #999;
  border-top:none;
  font-style:normal;
  padding:.5em;
  width:15em;
  }
h3{
     border:1px solid #000;
color:#fff;
background:#369;
padding:.2em .5em;
width:15em;
font-size:1em;
}
/* js enable */
body.dynamic address{
          background:#fff;
  border:none;
  font-style:normal;
  padding:.5em;
  border-top:1px solid #ccc;
  }
body.dynamic h3{
    padding-bottom:.5em;
background:#fff;
border:none;
}
body.dynamic h3 a{
color:#369;
}
var sc={

hidingClass:'hide',
DOMClass:'dynamic',
init:function(){
DOMhelp.cssjs('add',document.body,sc.DOMClass);
sc.head=document.getElementsByTagName('h3')[0];
sc.ad=DOMhelp.closestSibling(sc.head,1);
sc.ad.style.display='none';
DOMhelp.cssjs('add',sc.ad,sc.hidingClass);
var t=DOMhelp.getText(sc.head);
var collapselink=DOMhelp.createLink('#',t);
sc.head.replaceChild(collapselink,sc.head.firstChild);
DOMhelp.addEvent(collapselink,'click',sc.peekaboo,false);
collapselink.onclick=function(){return;}

},
peekaboo:function(e){
         if(DOMhelp.cssjs('check',sc.ad,sc.hidingClass))
{
DOMhelp.cssjs('remove',sc.ad,sc.hidingClass);
}else{
DOMhelp.cssjs('add',sc.ad,sc.hidingClass);
}
DOMhelp.cancelClick(e);
}
}
DOMhelp.addEvent(window,'load',sc.init,false);
主要想问下dy.css那个文件中*{
    margin:0;
padding:0;
}
什么意思干嘛加*啊？
body.dynamic address{
       。。
       。。
}这种写法是什么意思啊？
hidingClass:'hide',
DOMClass:'dynamic',
做什么用
？
JS可用时，DOMhelp.cssjs('add',document.body,sc.DOMClass);具体是什么意思怎么和dy.css那个文件联系起来理解？

解决方案 »

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主要想问下dy.css那个文件中*{
    margin:0;
padding:0;
}
什么意思干嘛加*啊？*代表通配符~·表示全部html标签用这个样式~·
body.dynamic address{
      。。
      。。
}这种写法是什么意思啊？表示body标签里class属性为dynamic的标签里<address>标签
DOMhelp.cssjs把这个放过发上来~·
/*
DOMhelp 1.0
written by Chris Heilmann
http://www.wait-till-i.com
To be featured in "Beginning JavaScript for Practical Web Development, Including  AJAX"
*/
DOMhelp={
debugWindowId:'DOMhelpdebug',
init:function(){
  if(!document.getElementById || !document.createTextNode){return;}
},
lastSibling:function(node){
  var tempObj=node.parentNode.lastChild;
  while(tempObj.nodeType!=1 && tempObj.previousSibling!=null){
   tempObj=tempObj.previousSibling;
  }
  return (tempObj.nodeType==1)?tempObj:false;
},
firstSibling:function(node){
  var tempObj=node.parentNode.firstChild;
  while(tempObj.nodeType!=1 && tempObj.nextSibling!=null){
   tempObj=tempObj.nextSibling;
  }
  return (tempObj.nodeType==1)?tempObj:false;
},
getText:function(node){
  if(!node.hasChildNodes()){return false;}
  var reg=/^\s+$/;
  var tempObj=node.firstChild;
  while(tempObj.nodeType!=3 && tempObj.nextSibling!=null || reg.test(tempObj.nodeValue)){
   tempObj=tempObj.nextSibling;
  }
  return tempObj.nodeType==3?tempObj.nodeValue:false;
},
setText:function(node,txt){
  if(!node.hasChildNodes()){return false;}
  var reg=/^\s+$/;
  var tempObj=node.firstChild;
  while(tempObj.nodeType!=3 && tempObj.nextSibling!=null || reg.test(tempObj.nodeValue)){
   tempObj=tempObj.nextSibling;
  }
  if(tempObj.nodeType==3){tempObj.nodeValue=txt}else{return false;}
},
createLink:function(to,txt){
  var tempObj=document.createElement('a');
  tempObj.appendChild(document.createTextNode(txt));
  tempObj.setAttribute('href',to);
  return tempObj;
},
createTextElm:function(elm,txt){
  var tempObj=document.createElement(elm);
  tempObj.appendChild(document.createTextNode(txt));
  return tempObj;
},
closestSibling:function(node,direction){
  var tempObj;
  if(direction==-1 && node.previousSibling!=null){
   tempObj=node.previousSibling;
   while(tempObj.nodeType!=1 && tempObj.previousSibling!=null){
     tempObj=tempObj.previousSibling;
   }
  }else if(direction==1 && node.nextSibling!=null){
   tempObj=node.nextSibling;
   while(tempObj.nodeType!=1 && tempObj.nextSibling!=null){
     tempObj=tempObj.nextSibling;
   }
  }
  return tempObj.nodeType==1?tempObj:false;
},
initDebug:function(){
  if(DOMhelp.debug){DOMhelp.stopDebug();}
  DOMhelp.debug=document.createElement('div');
  DOMhelp.debug.setAttribute('id',DOMhelp.debugWindowId);
  document.body.insertBefore(DOMhelp.debug,document.body.firstChild);
},
setDebug:function(bug){
  if(!DOMhelp.debug){DOMhelp.initDebug();}
  DOMhelp.debug.innerHTML+=bug+'\n';
},
stopDebug:function(){
  if(DOMhelp.debug){
   DOMhelp.debug.parentNode.removeChild(DOMhelp.debug);
   DOMhelp.debug=null;
  }
},
getKey:function(e){
  if(window.event){
       var key = window.event.keyCode;
     } else if(e){
       var key=e.keyCode;
     }
  return key;
},
/* helper methods */
getTarget:function(e){
  var target = window.event ? window.event.srcElement : e ? e.target : null;
  if (!target){return false;}
  while(target.nodeType!=1 && target.nodeName.toLowerCase()!='body'){
   target=target.parentNode;
  }
  return target;
},
stopBubble:function(e){
  if(window.event && window.event.cancelBubble){
   window.event.cancelBubble = true;
  }
  if (e && e.stopPropagation){
   e.stopPropagation();
  }
},
stopDefault:function(e){
  if(window.event && window.event.returnValue){
   window.event.returnValue = false;
  }
  if (e && e.preventDefault){
   e.preventDefault();
  }
},
cancelClick:function(e){
  if (window.event){
   window.event.cancelBubble = true;
   window.event.returnValue = false;
  }
  if (e && e.stopPropagation && e.preventDefault){
   e.stopPropagation();
   e.preventDefault();
  }
},
addEvent: function(elm, evType, fn, useCapture){
  if (elm.addEventListener){
   elm.addEventListener(evType, fn, useCapture);
   return true;
  } else if (elm.attachEvent) {
   var r = elm.attachEvent('on' + evType, fn);
   return r;
  } else {
   elm['on' + evType] = fn;
  }
},
cssjs:function(a,o,c1,c2){
  switch (a){
   case 'swap':
    o.className=!DOMhelp.cssjs('check',o,c1)?o.className.replace(c2,c1):o.className.replace(c1,c2);
   break;
   case 'add':
    if(!DOMhelp.cssjs('check',o,c1)){o.className+=o.className?' '+c1:c1;}
   break;
   case 'remove':
    var rep=o.className.match(' '+c1)?' '+c1:c1;
    o.className=o.className.replace(rep,'');
   break;
   case 'check':
    var found=false;
    var temparray=o.className.split(' ');
    for(var i=0;i<temparray.length;i++){
     if(temparray[i]==c1){found=true;}
    }
    return found;
   break;
  }
},
    safariClickFix:function(){
      return false;
    }
}
DOMhelp.addEvent(window, 'load', DOMhelp.init, false);
body中没有dynamic。
我觉得和这个有关DOMClass:'dynamic',但是具体我说不出它是什么意思。
我觉得和css有关
body.dynamic address{
      。。
      。。
}的语法规则是什么我不知道？主要想知道它的语法规则
这个的确跟DOMClass:'dynamic'有关，由DOMhelp.cssjs中引用，即o.className＝...(o为document.body)，这时body就引用上css中dynamic的class，从而改变了address标签的的样式