前端一段小脚本

        // 返回字符串长度，汉字以2个字符计算
        String.prototype.lenb = function () { return this.replace(/[^\x00-\xff]/g, '**').length; }

 

// 按字节长度截取字符串
        function cutstr(str, len, noPoint) {
            var l = str.lenb();
            if (l > len) {
                var cutlen = 0;
                var reallen = 0;
                for (var i = 0; i < str.length; i++) {
                    if (str.charAt(i).lenb() == 2)
                        cutlen++;
                    cutlen++;
                    if (cutlen >= len) {
                        str = str.substring(0, reallen);
                        if (!noPoint)
                            str += "..";
                        break;
                    }
                    reallen++;
                }
            }
            return str;
        }

 

 

//新浪注册要求密码格式，数字或组字母

    function requireNumberOrEng(val){
        if (val.length==0) return false;
        var intfmt=/^[+|-]?[a-zA-Z\d]+$/;
        if(!intfmt.test(val)) return false;
        return true;
    }