handleDefaultUseDoc(index) { let {id, documents} = this.travelerForm.travelers[index]; const { transnational } = this.checkList; let flightFlag = true, landFlag = true; if (id) { this.optionalDocument[index].length && this.optionalDocument[index].forEach(item => { if (documents.hasOwnProperty(item)) { this.handleDocClick(item, index); flightFlag = false; } }) this.landOptionalDoc[index].length && this.landOptionalDoc[index].forEach(item => { if (documents.hasOwnProperty(item)) { this.handleLandDoc(item, index); landFlag = false; } }) } if (flightFlag && this.optionalDocument.length && this.optionalDocument[index].length) { transnational ? this.handleDocClick('A', index) : this.handleDocClick(this.optionalDocument[index][0], index); } if (landFlag && this.landOptionalDoc.length && this.landOptionalDoc[index].length) { transnational ? this.handleLandDoc('A', index) : this.handleLandDoc(this.landOptionalDoc[index][0], index); } },

出来。 以下是一个可能的实现： ```c++ #include <iostream> #include <string> class TransitPerson { public: TransitPerson(int id) : id_(id) {} virtual ~TransitPerson() {} int get_id() const { return id_; } virtual std::string get_type() const = 0; virtual void print_info() const { std::cout << "ID: " << id_ << ", Type: " << get_type() << std::endl; } private: int id_; }; class Tourist : public TransitPerson { public: Tourist(int id, std::string country) : TransitPerson(id), country_(country) {} std::string get_type() const override { return "Tourist"; } std::string get_country() const { return country_; } void print_info() const override { std::cout << "ID: " << get_id() << ", Type: " << get_type() << ", Country: " << country_ << std::endl; } private: std::string country_; }; class TruckDriver : public TransitPerson { public: TruckDriver(int id, std::string license) : TransitPerson(id), license_(license) {} std::string get_type() const override { return "TruckDriver"; } std::string get_license() const { return license_; } void print_info() const override { std::cout << "ID: " << get_id() << ", Type: " << get_type() << ", License: " << license_ << std::endl; } private: std::string license_; }; class BusinessTraveler : public TransitPerson { public: BusinessTraveler(int id, std::string company) : TransitPerson(id), company_(company) {} std::string get_type() const override { return "BusinessTraveler"; } std::string get_company() const { return company_; } void print_info() const override { std::cout << "ID: " << get_id() << ", Type: " << get_type() << ", Company: " << company_ << std::endl; } private: std::string company_; }; int main() { const int kNumPersons = 6; TransitPerson* persons[kNumPersons] = { new Tourist(1, "USA"), new Tourist(2, "Japan"), new TruckDriver(3, "ABC123"), new TruckDriver(4, "XYZ789"), new BusinessTraveler(5, "Google"), new BusinessTraveler(6, "Microsoft") }; int num_tourists = 0; int num_truck_drivers = 0; int num_business_travelers = 0; for (int i = 0; i < kNumPersons; ++i) { persons[i]->print_info(); if (Tourist* tourist = dynamic_cast<Tourist*>(persons[i])) { ++num_tourists; std::cout << "Country: " << tourist->get_country() << std::endl; } else if (TruckDriver* truck_driver = dynamic_cast<TruckDriver*>(persons[i])) { ++num_truck_drivers; std::cout << "License: " << truck_driver->get_license() << std::endl; } else if (BusinessTraveler* business_traveler = dynamic_cast<BusinessTraveler*>(persons[i])) { ++num_business_travelers; std::cout << "Company: " << business_traveler->get_company() << std::endl; } } std::cout << "Num tourists: " << num_tourists << std::endl; std::cout << "Num truck drivers: " << num_truck_drivers << std::endl; std::cout << "Num business travelers: " << num_business_travelers << std::endl; for (int i = 0; i < kNumPersons; ++i) { delete persons[i]; } return 0; } ``` 这个程序定义了一个抽象基类 `TransitPerson`，包含一个唯一的数字标识符 `id_` 和一个纯虚函数 `get_type()`，表示该对象的类型。它还定义了三个派生类 `Tourist`、`TruckDriver` 和 `BusinessTraveler`，它们分别表示游客、卡车司机和商务旅客，每个类都重载了 `get_type()` 函数，返回相应的字符串，并添加了一些特定的字段和方法。 在 `main()` 函数中，我们创建了一个指向 `TransitPerson` 的指针数组 `persons`，并用几个不同的对象填充它。然后我们遍历该数组，对每个对象调用 `print_info()` 函数，打印出该对象的信息，并根据对象的类型统计对象的个数。最后，我们释放了所有的对象。 这个程序演示了如何使用抽象基类和派生类创建一个层次结构，以及如何使用动态类型转换和虚函数来处理不同类型的对象。