<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body>
<table width="500px" border="1px solid #ccc">
<thead>
<td>首页</td>
<td>数字</td>
<td>关于</td>
<td>我们</td>
</thead>
<tbody class="parent">
<!-- <tr>
<td>1</td>
<td class="small">2</td>
<td>3</td>
<td class="big" >5</td>
</tr> -->
</tbody>
</table>
<script type="text/javascript">
var parent=document.querySelectorAll(".parent")[0];
var tr="";
for(var i=0;i<9;i++){
tr+='<tr><td>1</td><td class="small">2</td><td>3</td><td class="big" >5</td></tr>'
};
parent.innerHTML=tr;
var small=document.querySelectorAll(".small");
var big=document.querySelectorAll(".big");
console.log(small);
console.log(big);
for(var j=0;j<small.length;j++){
if(big[j].innerHTML>small[j].innerHTML){
big[j].style.backgroundColor="red";
}else{
big[j].style.backgroundColor="white";
}
}
</script>
</body>
</html>
