js截取字符的长度

// 得到字符串的真实长度（双字节换算为两个单字节）
function getStrActualLen(sChars)
{
return sChars.replace(/[^\x00-\xff]/g,"xx").length;
}

// 截取固定长度子字符串 sSource为字符串iLen为长度
function getInterceptedStr(sSource, iLen)
{
if(sSource.replace(/[^\x00-\xff]/g,"xx").length <= iLen)
{
return sSource;
}
var ELIDED = "";

var str = "";
var l = 0;
var schar;
for(var i=0; schar=sSource.charAt(i); i++)
{
str += schar;
l += (schar.match(/[^\x00-\xff]/) != null ? 2 : 1);
if(l >= iLen - ELIDED.length)
{
break;
}
}
str += ELIDED;

return str;
}