一个简单的字符替换问题

Question

<script language=javascript>
var str="EditableGrid$ctl122$ctl00"
re=/(\$[a-z]+)(\d+)(\$)/gi
str=str.replace(re,function(a,b,c,d){return b+(parseInt(c)-1)+d})
alert(str)
</script>

Answer 1

楼上高人呀，这么简单，太棒了。再追问一下，如果我想在前面补0的话怎么做？如ctl10 - 1 得到 ctl09 ?

Answer 2

<script language=javascript>
var str="EditableGrid$ctl100$ctl00"
re=/(\$[a-z]+)(\d+)(\$)/gi
str=str.replace(re,function(a,b,c,d){var str="000"+(parseInt(c)-1).toString();str=str.substr(str.length-3); return b+str+d})
alert(str)
</script>