试试这个:
<HTML>
<BODY>
<script>
function trim(s)
{var re = new RegExp("(.*[^ ])( +)$","ig");
var arr = re.exec(s);
if(arr==null)
return s;
else
return RegExp.$1;
}var s1,s2;
s1=trim("abcd ");
alert("["+s1+"]");
s2=trim("1234");
alert("["+s2+"]");
</script>
</BODY>
</HTML>
<HTML>
<BODY>
<script>
function trim(s)
{var re = new RegExp("(.*[^ ])( +)$","ig");
var arr = re.exec(s);
if(arr==null)
return s;
else
return RegExp.$1;
}var s1,s2;
s1=trim("abcd ");
alert("["+s1+"]");
s2=trim("1234");
alert("["+s2+"]");
</script>
</BODY>
</HTML>
//去掉空格
lIdx=0;rIdx=str.length;
if (BASEtrim.arguments.length==2)
act=BASEtrim.arguments[1].toLowerCase();
else
act="all";
for(var i=0;i<str.length;i++){
thelStr=str.substring(lIdx,lIdx+1);
therStr=str.substring(rIdx,rIdx-1);
if ((act=="all" || act=="left") && thelStr==" "){
lIdx++;
}
if ((act=="all" || act=="right") && therStr==" "){
rIdx--;
}
}
str=str.slice(lIdx,rIdx);
return str;
}