JavaScript验证身份证号码是否合法

JavaScript验证身份证号码是否合法

/*
//身份证号合法性验证 
//支持15位和18位身份证号
//支持地址编码、出生日期、校验位验证
      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 = "";
          var pass= true;
          
          if(!code || !/^\d{6}(18|19|20)?\d{2}(0[1-9]|1[12])(0[1-9]|[12]\d|3[01])\d{3}(\d|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) alert(tip);
          return pass;
      }
     	var c = '130981199312253466';
     	var res= IdentityCodeValid(c);
alert(res);