c++ - '.setDay'左边的错误C2228必须具有类/结构/union

我的项目是对我们在类里面构建的项目的修改。例如，应该打印用户输入的日期，并将其转换为一年中的数字天。 “2月12日” = 43
但它一直给我一个.setDay错误。我的老师指示我把它放在那里，我的代码停止工作了，他无济于事。这也使错误E0299无法确定打算使用哪个重载函数“DayOfYear::DayOfYear”的实例。

修改文件

    // Headers
#include <iostream>
#include <cstdlib>
#include <string>
#include"DayOfYear.h"

using namespace std;


int main()
{
    // create an instance of a class
    DayOfYear dayOfYearObj("Feburary", 12);

    string month;
    int day;                                        // to hold the day

    // display the purpose of the program
    cout << "This program converts a string into a number representing what\n" <<
        "number in the year the date falls on as well as the day before and after the date provided.\n";

    // get the unout from the user
    cout << "\nEnter in a month and a date: ";
    cin >> month, day;

    dayOfYearObj;

    // diplsy the object
    dayOfYearObj.print();

    cout << endl;
    system("PAUSE");
    return 0;
}

DayOfYear.h

    #pragma once
#include<iostream>
#include<string>
using namespace std;

class DayOfYear
{
private:
    int day;

public:
    static int daysAtEndOfMonth[];
    static string monthName[];
    DayOfYear(string, int);
    void print();
    void setDay(int day) { this->day = day; }
};

DayOfYear.cpp

#include "DayOfYear.h"

int DayOfYear::daysAtEndOfMonth[] = { 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 };

string DayOfYear::monthName[] = { "January", "February", "March", "April", "May", "June", "July", "August", "September", "October",
"November", "December" };


DayOfYear::DayOfYear(string name, int d)
{
    int day = 0;        //calculated value of date

    if (name == "January" )
    {
        setDay(d);
    }

    else if (name == "February")
    {
        day = daysAtEndOfMonth[0] + d;
        DayOfYear::DayOfYear.setDay(d);
    }

    else if (name == "March")
    {
        day = daysAtEndOfMonth[1] + d;
        DayOfYear::DayOfYear.setDay(d);
    }

    else if (name == "April")
    {
        day = daysAtEndOfMonth[2] + d;
        DayOfYear::DayOfYear.setDay(d);
    }

    else if (name == "May")
    {
        day = daysAtEndOfMonth[3] + d;
        DayOfYear::DayOfYear.setDay(d);
    }

    else if (name == "June")
    {
        day = daysAtEndOfMonth[4] + d;
        DayOfYear::DayOfYear.setDay(d);
    }

    else if (name == "July")
    {
        day = daysAtEndOfMonth[5] + d;
        DayOfYear::DayOfYear.setDay(d);
    }

    else if (name == "August")
    {
        day = daysAtEndOfMonth[6] + d;
        DayOfYear::DayOfYear.setDay(d);
    }

    else if (name == "September")
    {
        day = daysAtEndOfMonth[7] + d;
        DayOfYear::DayOfYear.setDay(d);
    }

    else if (name == "October")
    {
        day = daysAtEndOfMonth[8] + d;
        DayOfYear::DayOfYear.setDay(d);
    }

    else if  (name == "November")
    {
        day = daysAtEndOfMonth[9] + d;
        DayOfYear::DayOfYear.setDay(d);
    }

    else if (name == "December")
    {
        day = daysAtEndOfMonth[10] + d;
        DayOfYear::DayOfYear.setDay(d);
    }
    else
    {
        cout << "Number is out of range." << endl;
    }
}


// dayofYear print convert and print day of year
void::DayOfYear::print()
{
    int month = 0;
    while (daysAtEndOfMonth[month] < day)
        month = (month + 1) % 12;
    if (month == 0)
        cout << "January" << day << endl << endl;
    else
    {
        cout << endl << monthName[month] << " " << day - daysAtEndOfMonth[month - 1]
            << endl << endl;
    }
}

最佳答案

setDay不是静态的，它需要从该类的实例中调用，所以您不能像这样调用它

DayOfYear::DayOfYear.setDay(d);

相反，您可以从this调用它

this->setDay(d);

这是在类方法中隐式调用的，因此您只需删除this->

setDay(d);

实际上，您可以对"January"正确执行此操作，然后在接下来的几个月中不正确。

关于c++ - '.setDay'左边的错误C2228必须具有类/结构/union ，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/58435902/