校验身份证号码

function IdentityCodeValid(code) {

    var city={11:"北京",12:"天津",13:"河北",14:"山西",15:"内蒙古",21:"辽宁",22:"吉林",23:"黑龙江 ",31:"上海",32:"江苏",33:"浙江",34:"安徽",35:"福建",36:"江西",37:"山东",41:"河南",42:"湖北 ",43:"湖南",44:"广东",45:"广西",46:"海南",50:"重庆",51:"四川",52:"贵州",53:"云南",54:"西藏 ",61:"陕西",62:"甘肃",63:"青海",64:"宁夏",65:"新疆",71:"台湾",81:"香港",82:"澳门",91:"国外 "};

    var tip = "身份证号合法";

    var pass= true;

    if(!code || !/(^\d{6}(\d{2})?\d{2}(0[1-9]|1[012])(0[1-9]|[12]\d|3[01])\d{3}(\d|X|x)$)/i.test(code)){

        tip = "身份证号格式错误";

        pass = false;

    }

    else if(!city[code.substr(0,2)]){

        tip = "地址编码错误";

        pass = false;

    }

    else{

        //18位身份证需要验证最后一位校验位

        if(code.length == 18){

            code = code.split('');

            //∑(ai×Wi)(mod 11)

            //加权因子

            var factor = [ 7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2 ];

            //校验位

            var parity = [ 1, 0, 'X', 9, 8, 7, 6, 5, 4, 3, 2 ];

            var sum = 0;

            var ai = 0;

            var wi = 0;

            for (var i = 0; i < 17; i++)

            {

                ai = code[i];

                wi = factor[i];

                sum += ai * wi;

            }

            var last = parity[sum % 11];

            if(parity[sum % 11] != code[17]){

                tip = "校验位错误";

                pass =false;

            }

        }

    }

    // if(!pass) console.log(tip);

    return pass;

}