var len = 0; for (var i=0; i127 || this.charCodeAt(i)==94) { len += 2; } else { len ++; return len;
function strlen(str){
    var len = 0;
    for (var i=0; i<str.length; i++) { 
     var c = str.charCodeAt(i); 
    //单字节加1 
     if ((c >= 0x0001 && c <= 0x007e) || (0xff60<=c && c<=0xff9f)) { 
       len++; 
     else { 
      len+=2; 
    return len;
var jmz = {};
jmz.GetLength = function(str) {
    ///<summary>获得字符串实际长度,中文2,英文1</summary>
    ///<param name="str">要获得长度的字符串</param>
    var realLength = 0, len = str.length, charCode = -1;
    for (var i = 0; i < len; i++) {
        charCode = str.charCodeAt(i);
        if (charCode >= 0 && charCode <= 128) realLength += 1;
        else realLength += 2;
    return realLength;
var l = str.length; 
var blen = 0; 
for(i=0; i<l; i++) { 
if ((str.charCodeAt(i) & 0xff00) != 0) { 
blen ++; 
blen ++; 

把双字节的替换成两个单字节的然后再获得长度

getBLen = function(str) {
	if (str == null) return 0;
	if (typeof str != "string"){
		str += "";
	return str.replace(/[^\x00-\xff]/g,"01").length;