怎么取得id为 "sub"+数字 的所有div?

Question

<div id="main">
   <div id="other">other</div>
   <div id="sub1">sub1</div>
   <div id="sub2">sub2</div>
   ...
</div>function hide()
{
for(i=0;i<document.getElementsByTagName("div").length;i++)
{
if(document.getElementsByTagName("div")[i].id.indexOf("sub")>-1)
{        document.getElementsByTagName("div")[i].style.backgroundColor = "green";
  }  
}

Answer 1

<div id="main">
<div id="other">other</div>
<div id="sub1">sub1</div>
<div id="sub2">sub2</div>
</div>
<input type=button value=doIt onclick=hide()>
<script>
function hide()
{
var divList = document.getElementById("main");
for(var i=0;i<divList.childNodes.length;i++)
{
if(divList.childNodes[i].id.substr(0, 3) == "sub")
divList.childNodes[i].style.backgroundColor = "green";
}
}

Answer 2

<div id="main">
   <div id="other">other</div>
   <div id="sub1">sub1</div>
   <div id="sub2">sub2</div>
   ...
</div>
<script>
function hide()
{
    var divList = document.getElementById("main").getElementsByTagName("div");
    for(var i=0;i<divList.length;i++)
    {
       if(divList[i].id&&divList[i].id.indexOf("sub")==0)
         divList[i].style.backgroundColor = "green";
    }
}
</script>