“11一“的长度为4

方法一：

function strLen(value) {
	var temlen=0;
	var len = 0;
	//是终的长度(1个汉字=2个字符)
	for(var i=0;i<value.length;i++){ 
		var c = value.substr(i,1); 
		var ts = escape(c); 
		if(ts.substring(0,2) == "%u"){
			len+=2;
			len+=temlen;
			temlen=0; 
		}else if(ts.substring(0,3) == "%0D"){
			temlen+=1; 
		}else if(ts.substring(0,3) == "%0A"){
			temlen+=1; 
		}else if(ts.substring(0,3) == "%20"){
			temlen+=1; 
		}else{
			len+=1;
			len+=temlen;
			temlen=0;
		}
	}
	return len;
}

方法二：

function strLen(str) {
    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;
}