此字符串比较不起作用

Question

所以当我输入我想要使用的月份时，例如 12 月，并且我将 722 作为小时数，程序会说：“您输入的小时数不能超过第 720 个月”。有没有办法解决？我不想每个月都做if语句，我觉得有一种更简单的方法。这也是我的第一个大学课程

int userPackage, userHours; //Declaring integer variables
double savings, savings2, total; //Declaring double value
string userMonth;
cout<<"\tHello.\nEnter the number of the package you have\n1) Package A\n2) Package B\n3) Package C\n"; //Prompts the user for their package in a menu like fashion
cin>>userPackage; //gets package
if(userPackage > 3 || userPackage < 1) //Error output for numbers that don't match packages
{
    cout<<"Error, invalid choice";
    return 0;
}

cout<<"Enter the number of hours you have been online."; //Propmts the user for the number of hours they've been online
cin>>userHours; //gets hours
cout<<"Enter the month (by name): ";
cin>>userMonth;
cout<<"\n";
if(userMonth == "January","March","May","July","August","October","December")
{
    if (userHours > 744)
    {
        cout<<"The amount of hours you entered cannot exceed the amount of hours within the month 744";
        return 0;
    }
}
if(userMonth == "April", "June", "September", "November");
{
    if(userHours > 720)
    {
        cout<<"The amount of hours you entered cannot exceed the amount of hours within the month 720";
        return 0;
    }
}
if(userMonth == "February");
{
    if (userHours > 672)
    {
        cout<<"The amount of hours you entered cannot exceed the amount of hours within the month 672";
        return 0;
    }   
}

Answer 1

if(userMonth == "January","March","May","July","August","October","December")

这并不像您认为的那样做（即，它不将userMonth 与每个字符串进行比较。您可能打算编写的语句（假设您也想使用else if 即使您的代码没有）：

if (userMonth == "January" ||
    userMonth == "March" ||
    userMonth == "July" ||
    userMonth == "August" ||
    userMonth == "October" ||
    userMonth == "December")
{
    ...
}
else if (userMonth == "April" ||
    userMonth == "June" ||
    userMonth == "September" ||
    userMonth == "November")
{
}
else if (userMonth == "February")
{
}

注意：这些也是区分大小写的比较（即，“一月”不等同于“一月”或任何其他大小写差异），最好将所有内容都转换为小写或全部大写。

if(userMonth == "April", "June", "September", "November");
// problematic trailing semi-colon ^

这将结束if 语句并且无条件执行下一个块。因此，当输入 722 时，它总是大于 720 并且您会收到您所看到的消息。

“二月”的 if 逻辑中也有同样的错误。