1 /*
 2 check(ID)验证身份证号码
 3 返回值：0 : "是正确的身份证号"
 4         1 : "身份证校验不符合求和模11=1这个等式",
 5         2 : "身份证最后一位校验位有误",
 6         3 : "身份证位数不正确",
 7         4 : "年份错误",
 8         5 : "月份错误",
 9         6 : "日错误"
10
11 */
12
13 function check(ID) {
14     var ck = new IDCard();
15     ck.check(ID);
16     return ck.errNum;
17 }
18
19 function IDCard(ID) {
20     var me = this;
21     this.checkCode = new Array(1, 0, 'X', 9, 8, 7, 6, 5, 4, 3, 2);
22     this.ID;
23     this.errNum = 0;
24     this.err = {
25         1 : "身份证校验不符合求和模11=1这个等式",
26         2 : "身份证最后一位校验位有误",
27         3 : "身份证位数不正确",
28         4 : "年份错误",
29         5 : "月份错误",
30         6 : "日错误"
31     };
32     this.err_msg = function() {
33         return (0 !== this.errNum) ? this.err[this.errNum] : null;
34     };
35     this.check = function(ID) {
36         this.errNum = 0;
37         this.ID = ID;
38         if (cardValidate()) {
39             if (!aiCheck()) this.errNum = 1;
40             if (!LastByteCheck()) this.errNum = 2;
41             return (0 === this.errNum) ? true: false;
42         } else {
43             return false;
44         }
45     };
46     function getNum(str) {
47         var re = /^[0]*([0-9]*)$/;
48         str.match(re);
49         return parseInt(RegExp.$1,10);
50     }
51     //对身份证位数，出生日期，初步验证
52     function cardValidate() {
53         var re = /^[0-9x]{15,18}$/i;
54         if (!re.test(me.ID)) {
55             me.errNum = 7;
56             return false;
57         }
58         if (15 == me.ID.length || 18 == me.ID.length) {
59             var realLen = 0;
60             if (18 == me.ID.length) realLen = 2;
61             var year = parseInt(me.ID.substr(6, 2 + realLen),10);
62             var month = getNum(me.ID.substr(8 + realLen, 2));
63             var day = parseInt(me.ID.substr(10 + realLen, 2),10);
64             if (4 == year.length) if (year < 1900 || year > 2050) me.errNum = 4;
65             if (month < 1 || month > 12) me.errNum = 5;
66             if (day < 1 || day > 31) me.errNum = 6;
67             return 0 === me.errNum;
68         } else {
69             me.errNum = 3;
70             return false;
71         }
72     }
73     //总和模11应该等于1
74     var aiCheck = function() {
75         var sum = 0;
76         for (var i = 1; i <= me.ID.length; i++) {
77             var ai = me.ID.substr(me.ID.length - i, 1);
78             ai = (ai.toLowerCase() == 'x') ? 10 : ai;
79             var wi = Math.pow(2, i - 1) % 11;
80             sum += parseInt(ai,10) * wi;
81         }
82         return 1 == sum % 11;
83     };
84     //最后一位校验，这个可以和aiCheck合在一起，减少一次循环
85     var LastByteCheck = function() {
86         var sum = 0;
87         for (var i = 2; i <= me.ID.length; i++) {
88             var ai = me.ID.substr(me.ID.length - i, 1);
89             ai = (ai.toLowerCase() == 'x') ? 10 : ai;
90             var wi = Math.pow(2, i - 1) % 11;
91             sum += parseInt(ai,10) * wi;
92         }
93         var checkCodeIndex = sum % 11;
94         var c = me.ID.substr(me.ID.length - 1, 1);
95         //alert(c+"=="+me.checkCode[checkCodeIndex]);
96         return c == me.checkCode[checkCodeIndex];
97     };
98 }