实现效果

• 验证 15 位或 18 位身份证号的格式
• 检验身份证号的有效性

- (BOOL)validateIDCardNumber:(NSString *)idCardNumber {
    
    idCardNumber = [idCardNumber stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
    NSInteger length =0;
    if (!idCardNumber) {
        return NO;
    }else {
        length = idCardNumber.length;
        //不满足15位和18位，即身份证错误
        if (length !=15 && length !=18) {
            return NO;
        }
    }
    // 省份代码
    NSArray *areasArray = @[@"11",@"12", @"13",@"14", @"15",@"21", @"22",@"23", @"31",@"32", @"33",@"34", @"35",@"36", @"37",@"41", @"42",@"43", @"44",@"45", @"46",@"50", @"51",@"52", @"53",@"54", @"61",@"62", @"63",@"64", @"65",@"71", @"81",@"82", @"91"];
    
    // 检测省份身份行政区代码
    NSString *valueStart2 = [idCardNumber substringToIndex:2];
    BOOL areaFlag =NO; //标识省份代码是否正确
    for (NSString *areaCode in areasArray) {
        if ([areaCode isEqualToString:valueStart2]) {
            areaFlag =YES;
            break;
        }
    }
    
    if (!areaFlag) {
        return NO;
    }
    
    NSRegularExpression *regularExpression;
    NSUInteger numberofMatch;
    
    int year =0;
    //分为15位、18位身份证进行校验
    switch (length) {
        case 15:
            //获取年份对应的数字
            year = [idCardNumber substringWithRange:NSMakeRange(6,2)].intValue +1900;
            
            if (year %4 ==0 || (year %100 ==0 && year %4 ==0)) {
                //创建正则表达式 NSRegularExpressionCaseInsensitive：不区分字母大小写的模式
                //测试出生日期的合法性
                regularExpression = [[NSRegularExpression alloc]initWithPattern:@"^[1-9][0-9]{5}[0-9]{2}((01|03|05|07|08|10|12)(0[1-9]|[1-2][0-9]|3[0-1])|(04|06|09|11)(0[1-9]|[1-2][0-9]|30)|02(0[1-9]|[1-2][0-9]))[0-9]{3}$" options:NSRegularExpressionCaseInsensitive error:nil];
            }else {
                //测试出生日期的合法性
                regularExpression = [[NSRegularExpression alloc]initWithPattern:@"^[1-9][0-9]{5}[0-9]{2}((01|03|05|07|08|10|12)(0[1-9]|[1-2][0-9]|3[0-1])|(04|06|09|11)(0[1-9]|[1-2][0-9]|30)|02(0[1-9]|1[0-9]|2[0-8]))[0-9]{3}$" options:NSRegularExpressionCaseInsensitive error:nil];
            }
            //使用正则表达式匹配字符串 NSMatchingReportProgress:找到最长的匹配字符串后调用block回调
            numberofMatch = [regularExpression numberOfMatchesInString:idCardNumber options:NSMatchingReportProgress range:NSMakeRange(0, idCardNumber.length)];
            
            if(numberofMatch >0) {
                return YES;
            }else {
                return NO;
            }
        case 18:
            year = [idCardNumber substringWithRange:NSMakeRange(6,4)].intValue;
            if (year %4 ==0 || (year %100 ==0 && year %4 ==0)) {
                regularExpression = [[NSRegularExpression alloc]initWithPattern:@"^[1-9][0-9]{5}19[0-9]{2}((01|03|05|07|08|10|12)(0[1-9]|[1-2][0-9]|3[0-1])|(04|06|09|11)(0[1-9]|[1-2][0-9]|30)|02(0[1-9]|[1-2][0-9]))[0-9]{3}[0-9Xx]$" options:NSRegularExpressionCaseInsensitive error:nil];//测试出生日期的合法性
            }else {
                regularExpression = [[NSRegularExpression alloc]initWithPattern:@"^[1-9][0-9]{5}19[0-9]{2}((01|03|05|07|08|10|12)(0[1-9]|[1-2][0-9]|3[0-1])|(04|06|09|11)(0[1-9]|[1-2][0-9]|30)|02(0[1-9]|1[0-9]|2[0-8]))[0-9]{3}[0-9Xx]$" options:NSRegularExpressionCaseInsensitive error:nil];//测试出生日期的合法性
            }
            numberofMatch = [regularExpression numberOfMatchesInString:idCardNumber options:NSMatchingReportProgress range:NSMakeRange(0, idCardNumber.length)];
            
            
            if(numberofMatch >0) {
                //1：校验码的计算方法 身份证号码17位数分别乘以不同的系数。从第一位到第十七位的系数分别为：7－9－10－5－8－4－2－1－6－3－7－9－10－5－8－4－2。将这17位数字和系数相乘的结果相加。
                
                int S = [idCardNumber substringWithRange:NSMakeRange(0,1)].intValue*7 + [idCardNumber substringWithRange:NSMakeRange(10,1)].intValue *7 + [idCardNumber substringWithRange:NSMakeRange(1,1)].intValue*9 + [idCardNumber substringWithRange:NSMakeRange(11,1)].intValue *9 + [idCardNumber substringWithRange:NSMakeRange(2,1)].intValue*10 + [idCardNumber substringWithRange:NSMakeRange(12,1)].intValue *10 + [idCardNumber substringWithRange:NSMakeRange(3,1)].intValue*5 + [idCardNumber substringWithRange:NSMakeRange(13,1)].intValue *5 + [idCardNumber substringWithRange:NSMakeRange(4,1)].intValue*8 + [idCardNumber substringWithRange:NSMakeRange(14,1)].intValue *8 + [idCardNumber substringWithRange:NSMakeRange(5,1)].intValue*4 + [idCardNumber substringWithRange:NSMakeRange(15,1)].intValue *4 + [idCardNumber substringWithRange:NSMakeRange(6,1)].intValue*2 + [idCardNumber substringWithRange:NSMakeRange(16,1)].intValue *2 + [idCardNumber substringWithRange:NSMakeRange(7,1)].intValue *1 + [idCardNumber substringWithRange:NSMakeRange(8,1)].intValue *6 + [idCardNumber substringWithRange:NSMakeRange(9,1)].intValue *3;
                
                //2：用加出来和除以11，看余数是多少？余数只可能有0－1－2－3－4－5－6－7－8－9－10这11个数字
                int Y = S %11;
                NSString *M =@"F";
                NSString *JYM =@"10X98765432";
                M = [JYM substringWithRange:NSMakeRange(Y,1)];// 3：获取校验位
                
                NSString *lastStr = [idCardNumber substringWithRange:NSMakeRange(17,1)];
                
                NSLog(@"%@",M);
                NSLog(@"%@",[idCardNumber substringWithRange:NSMakeRange(17,1)]);
                //4：检测ID的校验位
                if ([lastStr isEqualToString:@"x"]) {
                    if ([M isEqualToString:@"X"]) {
                        return YES;
                    }else{
                        
                        return NO;
                    }
                }else{
                    
                    if ([M isEqualToString:[idCardNumber substringWithRange:NSMakeRange(17,1)]]) {
                        return YES;
                    }else {
                        return NO;
                    }
                    
                }
                
            }else {
                return NO;
            }
        default:
            return NO;
    }
}

个人博客：https://mortal-master.github.io