JS判断字符串长度的5个方法（区分中文和英文）

String.prototype.gblen = function() { 
  var len = 0; 
  for (var i=0; i<this.length; i++) { 
    if (this.charCodeAt(i)>127 || 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 ++;
}

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