Question

// Would someone please help me figure out how to get C++ to accept my inputed month value as a decimal, by in-turn change it to an integer?

#include <iostream>
using namespace std;

int main()
{
    int month, day, year;
    cout << "Enter a month (use 1 for january, ect.): ";
    cin  >> month;
    
    cout << "Enter a day of the month: ";
    cin  >>  day;
    
    cout << month << "/" << day << endl;
    

    if ( day == (int) day )
    {                        // Day must be an integer quantity.
    }
        else
        {
            cout << "day is invalid" << endl;   
        }
            if ( (month < 1 ) || ( month > 12) )
            {
                cout << "Month value is invalid." << endl;
            }
                if ( (day < 1 ) || ( day > 31) )  
                {
                    cout << "Day value is invalid." << endl;
                }
    
    switch (month)
    {
        case 9:     // September
        case 4:     // April
        case 6:     // June
        case 11:    // November
        {
            if ( day > 30 )
            {
                cout << "Day value is invalid." << endl;
            }
        }
        break;
        
        case 2:     // February
        {
            if ( day > 28 )
            {
                cout << "Day value is invalid." << endl;
            }
        }
        break;
    }
    
   return 0;
}

Answer 1

If your just trying to get a decimal input, you can just change the your initialization of month to "double month" instead of "int month."

If you want an int input and then have it become a decimal you can just create a new variable for your decimal month and set it equal to the int month:

double dMonth = month; //c++ and most other languages will convert an int to a floating-point number if need be