13.阅读程序，写出运行结果，说明原因 #include<iostream.h> class example. public: example(int n){i=n;cout <<"Constructing\n"} ~example(){cout<<"Destructingn\n”} int get i(){return i;} private:{int i}; int sqr_it(example o){return o.get-i()*o.get_i();} int main(){ example x(10); cout <<x.get_i()<<endl: cout<<sqr_it()<<endl; retun 0; }

这段代码存在一些语法错误，应该是这样的：

#include<iostream>
using namespace std;

class example {
public:
    example(int n) {
        i = n;
        cout << "Constructing\n";
    }
    ~example() {
        cout << "Destructing\n";
    }
    int get_i() {
        return i;
    }
private:
    int i;
};

int sqr_it(example o) {
    return o.get_i() * o.get_i();
}

int main() {
    example x(10);
    cout << x.get_i() << endl;
    cout << sqr_it(x) << endl;
    return 0;
}

运行结果为：

Constructing
10
Destructing
100

原因是，首先在 `main` 函数中创建了 `example` 类的一个对象 `x`，并且输出了其成员变量 `i` 的值，即 `10`。然后调用 `sqr_it` 函数，将 `x` 作为参数传入，该函数返回 `x.i * x.i`，即 `100`。最后 `main` 函数结束，`x` 对象自动销毁，输出析构函数的提示信息。

相关问题

#include <iostream> #include <string> #include <iomanip> using namespace std; class house{ private: string location; int num_of_rooms; int year_built; public: house(); house(string,int,int); void set_location(string); string get_location(); void set_num_of_rooms(int); int get_num_of_rooms(); void set_year_built(int); int get_year_built(); void print_house_details(); };

This is a class declaration for a `house` class with some private member variables and public member functions. Here is an example implementation for the `house_impl.cpp` file:

#include "house.h"

// Default constructor
house::house() {
    location = "";
    num_of_rooms = 0;
    year_built = 0;
}

// Parameterized constructor
house::house(string loc, int num, int year) {
    location = loc;
    num_of_rooms = num;
    year_built = year;
}

// Setter and getter functions for location
void house::set_location(string loc) {
    location = loc;
}

string house::get_location() {
    return location;
}

// Setter and getter functions for number of rooms
void house::set_num_of_rooms(int num) {
    num_of_rooms = num;
}

int house::get_num_of_rooms() {
    return num_of_rooms;
}

// Setter and getter functions for year built
void house::set_year_built(int year) {
    year_built = year;
}

int house::get_year_built() {
    return year_built;
}

// Function to print house details
void house::print_house_details() {
    cout << "Location: " << location << endl;
    cout << "Number of rooms: " << num_of_rooms << endl;
    cout << "Year built: " << year_built << endl;
}

Note that the implementation file should include the header file `house.h` which contains the declaration of the `house` class.

帮我利用以下头文件内容编写一个C++程序，依据某DBC文件进行CAN报文发送。 #ifndef __DBC_HPP__ //头文件保护 #define __DBC_HPP__ #include <libdbc/exceptions/error.hpp> #include <libdbc/message.hpp> #include <libdbc/signal.hpp> #include <libdbc/utils/utils.hpp> #include <regex> namespace libdbc { class Parser { public: virtual ~Parser() = default; virtual void parse_file(const std::string& file) = 0; protected: }; class DbcParser : public Parser { public: DbcParser(); virtual ~DbcParser() = default; virtual void parse_file(const std::string& file) final override; std::string get_version() const; std::vector<std::string> get_nodes() const; std::vector<libdbc::Message> get_messages() const; Message::ParseSignalsStatus parseMessage(const uint32_t id, const std::vector<uint8_t>& data, std::vector<double>& out_values); private: std::string version; std::vector<std::string> nodes; std::vector<libdbc::Message> messages; const std::regex version_re; const std::regex bit_timing_re; const std::regex name_space_re; const std::regex node_re; const std::regex message_re; const std::regex signal_re; void parse_dbc_header(std::istream& file_stream); void parse_dbc_nodes(std::istream& file_stream); void parse_dbc_messages(const std::vector<std::string>& lines); }; } #endif // __DBC_HPP__

这是一个DBC文件解析的C++头文件，其中包含了DBC文件的解析类Parser以及DbcParser，可以用于解析DBC文件中的版本信息、节点信息、消息信息和信号信息等。以下是一个简单的例子，展示如何使用DbcParser类解析DBC文件并发送CAN报文：

#include <iostream>
#include <vector>
#include "dbc.hpp"

int main() {
    // 创建DbcParser对象
    libdbc::DbcParser parser;
    // 解析DBC文件
    parser.parse_file("example.dbc");
    // 获取解析结果
    std::string version = parser.get_version();
    std::vector<std::string> nodes = parser.get_nodes();
    std::vector<libdbc::Message> messages = parser.get_messages();

    // 构造CAN报文
    uint32_t id = 0x123;
    std::vector<uint8_t> data = {0x01, 0x02, 0x03};
    libdbc::Message::ParseSignalsStatus status;
    std::vector<double> out_values;
    for (auto& msg : messages) {
        if (msg.get_id() == id) {
            status = parser.parseMessage(id, data, out_values);
            break;
        }
    }
    if (status == libdbc::Message::ParseSignalsStatus::OK) {
        // 发送CAN报文
        // ...
        std::cout << "CAN message sent successfully!" << std::endl;
    } else {
        std::cerr << "Failed to parse CAN message signals!" << std::endl;
    }

    return 0;
}

需要注意的是，这仅仅是一个简单的例子，实际操作需要根据DBC文件的具体内容和CAN总线通信的实际情况进行修改和调整。