C# - program to display all of the same days dates in the month, user input

Question

i need guidance on how i can display for example all monday dates in a month, based on user input, can be any day and any month. my code so far is here but doesn't seem to display the dates. of the specified day i input, where has this gone wrong, any help is really appreciated.

using System;
using System.Globalization;

namespace Calendar
{
   class Program
   {
        static int promptDay = new int();
        static int year = new int();
        static int month = new int();
        static int[,] calendar = new int[6, 7];

        static void Main(string[] args)
        {
            Console.Write("Enter the year? ");
            year = Convert.ToInt32(Console.ReadLine());
            Console.Write("Enter the month (January = 1, etc): ");
            month = Convert.ToInt32(Console.ReadLine());
            Console.Write("Enter the day you want to see the dates for (Mon = 0, etc): ");
            promptDay = Convert.ToInt32(Console.ReadLine());
            DrawHeader();
            FillCalendar();
            DrawCalendar();
            Console.ReadLine();
        }

        static void DrawHeader()
        {
            Console.Write("\n\n");
            //gives you the month and year at the top of the calendar
            Console.WriteLine(CultureInfo.CurrentCulture.DateTimeFormat.GetMonthName(month) + " " + year);
            Console.WriteLine("Mo Tu We Th Fr Sa Su");
        }

        static void FillCalendar()
        {
            int currentDay = 1;
            for (int i = 0; i < calendar.GetLength(0); i++)
            {
                for (int j = 0; j < calendar.GetLength(1) && currentDay <= totalDays; j++)
                {
                    if (i == 0 && day > j)
                    {
                        calendar[i, j] = 0;
                    }
                    else
                    {
                        if (j != promptDay)
                        {
                            calendar[i, j] = 0;
                        }
                        else
                        {
                            calendar[i, j] = currentDay;
                        }
                        currentDay++;
                    }
                }
            }
        }

        static void DrawCalendar()
        {
            for (int i = 0; i < calendar.GetLength(0); i++)
            {
                for (int j = 0; j < calendar.GetLength(1); j++)
                {
                    if (calendar[i, j] > 0)
                    {
                        if (calendar[i, j] < 10)
                        {
                            Console.Write(" " + calendar[i, j] + " ");
                        }
                        else
                        {
                            Console.Write(calendar[i, j] + " ");
                        }
                    }
                    else
                    {
                        Console.Write("   ");
                    }
                }
                Console.WriteLine("");
            }
        }
    }
}

Possible duplicate of [How do i get all the weekdays and dates in a month](http://stackoverflow.com/questions/12903663/how-do-i-get-all-the-weekdays-and-dates-in-a-month) — Mong Zhu, Dec 01 '16 at 15:22
yh i tried that but it doesnt ask for user input?? how can i get that? — J.Doe, Dec 01 '16 at 15:23
your for-loop never runs because you never assign `int days` any value. By default it is `0`. So no values are added into your list. Don't you want to ask the user once for the "weekday" ? and not on every iteration ? — Mong Zhu, Dec 01 '16 at 15:30
Which day do you want to look at (Mon = 0, etc)? 1 The Tuesdays of the month are: 4 11 18 25 — J.Doe, Dec 01 '16 at 15:30
actually you could make your life very simple. Find the first day that is a Tuesday for example and then count up in steps of 7 until you overstep `totalDays` — Mong Zhu, Dec 01 '16 at 15:32
i dont have to use tuesdays, i need the day and month based on user input and how could i implement what you have just suggested — J.Doe, Dec 01 '16 at 15:34
i tried the duplicate you said at the start but it gives an error when i install console.write for user input to return weeday — J.Doe, Dec 01 '16 at 15:37
So basically you want a method like `public static IEnumerable GetDays(int year, int month, DayOfWeek dayOfWeek) { DateTime value = new DateTime(year, month, 1); while (value.Month == month) { if (value.DayOfWeek == dayOfWeek) { yield return value.Day; } value = value.AddDays(1); } }, right?` — Corak, Dec 01 '16 at 15:37
Or if you're uncomfortable with `IEnumerable` and `yield`, maybe: `public static List GetDays(int year, int month, DayOfWeek dayOfWeek) { List result = new List(); DateTime value = new DateTime(year, month, 1); while (value.Month == month) { if (value.DayOfWeek == dayOfWeek) { result.Add(value.Day); } value = value.AddDays(1); } return result; }` — Corak, Dec 01 '16 at 15:40
i dont understand, can u just make some changes to the code i had given in the question — J.Doe, Dec 01 '16 at 15:41
@J.Doe - I don't understand your code. But it seems like you *have* the `year` and the `month` and the `dayOfWeek` as user inputs and *want* to display the "day numbers" of each of the given `dayOfWeek`s in that month. — Corak, Dec 01 '16 at 15:43
i changed the code based on people's suggestion, please look at the code now and my question — J.Doe, Dec 01 '16 at 15:46
Well, your code doesn't compile. Please be sure to follow these suggestions: http://stackoverflow.com/help/mcve — Corak, Dec 01 '16 at 15:50
However, rather than displaying a calendar, you should ask for a different day and output which dates in the month fall on that day. An example of the output from this program could be: Enter the day the first falls on (Mon = 0, etc): 5 How many days in the month? 31 Which day do you want to look at (Mon = 0, etc)? 1 The Tuesdays of the month are: 4 11 18 25 — J.Doe, Dec 01 '16 at 15:53
@J.Doe - Well, if it's not "you *have* the `year` and the `month` and the `dayOfWeek` as user inputs and *want* to display the 'day numbers' of each of the given `dayOfWeek`s in that month.", then no, I don't understand your question. — Corak, Dec 01 '16 at 15:54
ok i'll explain again, so basically i need user input on days in a month and month name, and day (mon,tues,wed,etc..) and then the ouput should display the dates for the day specified by the user, for example if the user entered monday and november the output should display the dates for the monday in november — J.Doe, Dec 01 '16 at 15:57
@J.Doe - ah, you see? "Enter the day the first falls on (Mon = 0, etc)" is quite different from what you have. — Corak, Dec 01 '16 at 15:57
yh i am sorry if it is a mess of a code, i am just a beginner — J.Doe, Dec 01 '16 at 15:58

Sid · Accepted Answer · 2016-12-01T16:07:26.090

The following code prints out all the days for a given DayOfWeek, yes it can be improved but it's just a starting point

OutPut

What is the year? : 2016
What is the name of the month? : dicembre
Monday
5 12 19 26
Thursday
1 8 15 22 29
Wednesday
7 14 21 28
Tuesday
6 13 20 27
Friday
2 9 16 23 30
Saturday
3 10 17 24 31
Sunday
4 11 18 25

Note that dicembre is december in Italian.

Dictionary<DayOfWeek, List<int>> daysCount = new Dictionary<DayOfWeek, List<int>>()
{
    { DayOfWeek.Monday, new List<int>() },
    { DayOfWeek.Thursday, new List<int>() },
    { DayOfWeek.Wednesday, new List<int>() },
    { DayOfWeek.Tuesday, new List<int>() },
    { DayOfWeek.Friday, new List<int>() },
    { DayOfWeek.Saturday, new List<int>() },
    { DayOfWeek.Sunday, new List<int>() },
};

Console.Write("What is the year? : ");
var year = Convert.ToInt32(Console.ReadLine());
Console.Write("What is the name of the month? : ");
var monthName = Console.ReadLine();

var monthNumber = DateTime.ParseExact(monthName, "MMMM", CultureInfo.CurrentCulture).Month;
var dayOfMonth = DateTime.DaysInMonth(year, monthNumber);

var date = new DateTime(year, monthNumber, 1);


for(int i = 0; i < dayOfMonth; i++, date = date.AddDays(1))
{

    if (daysCount[date.DayOfWeek] == null)
    {
        daysCount[date.DayOfWeek] = new List<int>();
    }

    daysCount[date.DayOfWeek].Add(date.Day);
}

foreach (var day in daysCount)
{
    Console.WriteLine(day.Key.ToString());
    foreach (var dayNumber in day.Value)
    {
        Console.Write(string.Format("{0} ", dayNumber));
    }
    Console.WriteLine();

}

Console.ReadLine();

Variant to show only user specified day

Notice that Sunday = 0

var days = new List<int>();
Console.Write("What is the year? : ");
var year = Convert.ToInt32(Console.ReadLine());
Console.Write("What is the name of the month? : ");
var monthName = Console.ReadLine();
Console.Write("Enter the day you want to see the dates for (Mon = 0, etc): ");
var promptDay = Convert.ToInt32(Console.ReadLine());

var monthNumber = DateTime.ParseExact(monthName, "MMMM", CultureInfo.CurrentCulture).Month;
var dayOfMonth = DateTime.DaysInMonth(year, monthNumber);

var date = new DateTime(year, monthNumber, 1);


for(int i = 0; i < dayOfMonth; i++, date = date.AddDays(1))
{

    if ((int)date.DayOfWeek == promptDay)
        days.Add(date.Day);
}

foreach (var day in days)
{
    Console.Write(string.Format("{0} ", day));

}

Console.ReadLine();

how can i change it so it just displays the one day entered by the user, so just monday, etc... — J.Doe, Dec 01 '16 at 15:59
the type or namespace dictionary couldnt be found, are you missing a reference — J.Doe, Dec 01 '16 at 16:05
@J.Doe i've updated the answer, to resolve your error insert `using System.Collections.Generic;` at the top — Sid, Dec 01 '16 at 16:08
do you have email that i can save for future contact, as i am so grateful for this!! — J.Doe, Dec 01 '16 at 16:13
not skype? anything else i dont use skype, like gmail or something — J.Doe, Dec 01 '16 at 16:14

C# - program to display all of the same days dates in the month, user input

1 Answers1

Variant to show only user specified day