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Thread: Homework - Calendar Assignment

  1. #1
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    Default Homework - Calendar Assignment

    Hi, I'm stuck on this project. This is the instructions:

    CMPS 135 Programming Assignment 4

    Problem:
    Write a Java program to print out the calendar of any year provided that the day of January 1 of that year is known. (Note: Leap year is a year whose number is divisible by 4. The Feb. of a leap year has 29 days. You will receive extra points if you can print the calendar with 3 months in a row.)

    Specification:
    Use modular programming to write the program.





    Currently, this is the code I have, but the program isn't working correctly:

    import javax.swing.JOptionPane;
     
    public class Assignment4Test
    {
    public static void display()
    { System.out.println(" S M T W T F S");
    System.out.println("---------------------");
    }
     
    public static void main(String args[])
     
    { int year; 
    String yearstr; 
    int startday; 
    String startdaystr; 
    int month; 
    int daysinmonth; 
    String monthname; 
    int spacesforstartday;
    int date; 
     
    yearstr = JOptionPane.showInputDialog("What is the number of the year?");
    year = Integer.parseInt(yearstr);
     
    startdaystr = JOptionPane.showInputDialog("What is the day of January 1? (S-1 M-2 T-3 W-4 T-5 F-6 S-7)");
    startday = Integer.parseInt(startdaystr);
     
    System.out.println(" "+year);
    System.out.println(" ===="); 
     
    for (month=1; month<=12; month++)
    {
    monthname="";
    daysinmonth=0;
    switch (month)
    {
     
    case 1:
     
    monthname="Jan ";
    daysinmonth=31;
    break;
     
    case 2:
     
    monthname="Feb ";
    if (year%4 == 0 && year%100 != 0 || year%400 == 0)
    { daysinmonth = 29; }
    else
    { daysinmonth = 28; }
    break;
     
    case 3:
     
    monthname = "March ";
    daysinmonth = 31;
    break;
     
    case 4:
     
    monthname="April ";
    daysinmonth = 30;
    break;
     
    case 5:
     
    monthname="May ";
    daysinmonth = 31;
    break;
     
    case 6:
     
    monthname="June ";
    daysinmonth = 30;
    break;
     
    case 7:
     
    monthname="July ";
    daysinmonth = 31;
    break;
     
    case 8:
     
    monthname="Aug ";
    daysinmonth = 31;
    break;
     
    case 9:
     
    monthname="Sept ";
    daysinmonth = 30;
    break;
     
    case 10:
     
    monthname="Oct ";
    daysinmonth = 31;
    break;
     
    case 11:
     
    monthname="Nov ";
    daysinmonth = 30;
    break;
     
    case 12:
     
    monthname="Dec ";
    daysinmonth = 31;
    break;
     
    default:
     
    System.out.println("Invalid data");
    break;
     
    }
     
    System.out.println("");
    System.out.println(" "+monthname);
    System.out.println("");
     
    display();
     
    for(spacesforstartday=1;spacesforstartday<=startday;spacesforstartday++)
    {System.out.print(" ");}
     
    for(date=1; date<=daysinmonth; date++)
    { 
    if(startday%7 == 0 && startday != 0)
    {System.out.println();}
    if(date<10)
    {System.out.print(" "+date);}
    else
    {System.out.print(" "+date);}
    startday=startday+1;
    }
     
     
     
    startday%=7;
    System.out.println("");
    System.out.println("");
    }
     
     
     
    System.exit(0);
     
    }}


  2. #2
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    Default Re: Homework - Calendar Assignment

    program isn't working correctly:
    Please explain. Show what the program currently does and add some comments saying what the output should be.

    Please edit your post and wrap your code with code tags:
    [code=java]
    <YOUR CODE HERE>
    [/code]
    to get highlighting and preserve formatting.
    If you don't understand my answer, don't ignore it, ask a question.

  3. #3
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    Default Re: Homework - Calendar Assignment

    It's basically just supposed to print out a calendar, however for some reason the 1st of january always comes out one day early, which throws off the whole calendar.

  4. #4
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    Default Re: Homework - Calendar Assignment

    Can you post the contents of the console window from when you execute the program? Add some comments saying what is wrong with the output and show what it should be.


    What happened to the formatting of the code? All the statements should NOT start in the first column.
    Statements nested within {}s should be indented 3-4 spaces.
    Unformatted code is hard to read and understand.
    If you don't understand my answer, don't ignore it, ask a question.

  5. #5
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    Default Re: Homework - Calendar Assignment

    Untitled.jpg
    I uploaded a picture, the formatting was really messed up when copy/pasting it.

  6. #6
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    Default Re: Homework - Calendar Assignment

    Use code tags around the program's output to preserve its formatting.
    Add some comments saying what is wrong with the output.


    What happened to the formatting of the code? All the statements should NOT start in the first column.
    Statements nested within {}s should be indented 3-4 spaces.
    Unformatted code is hard to read and understand.
    If you don't understand my answer, don't ignore it, ask a question.

  7. #7
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    Default Re: Homework - Calendar Assignment

    import javax.swing.JOptionPane;
     
    public class Assignment4Test
    {
      public static void display()
      { System.out.println("  S  M  T  W  T  F  S");
        System.out.println("---------------------");
      }
     
       public static void main(String args[])
     
      { int year;              
        String yearstr;        
        int startday;              
        String startdaystr;        
        int month;             
        int daysinmonth;             
        String monthname;          
        int spacesforstartday;
        int date;           
     
        yearstr = JOptionPane.showInputDialog("What is the number of the year?");
        year = Integer.parseInt(yearstr);
     
        startdaystr = JOptionPane.showInputDialog("What is the day of January 1? (S-1 M-2 T-3 W-4 T-5 F-6 S-7)");
        startday = Integer.parseInt(startdaystr);
     
        System.out.println("          "+year);
        System.out.println("          ====");      
     
        for (month=1; month<=12; month++)
        {
          monthname="";
          daysinmonth=0;
          switch (month)
          {
     
            case 1:
     
              monthname="Jan ";
              daysinmonth=31;
              break;
     
            case 2:
     
              monthname="Feb ";
              if (year%4 == 0 && year%100 != 0 || year%400 == 0)
              { daysinmonth = 29; }
              else
              { daysinmonth = 28; }
              break;
     
            case 3:
     
              monthname = "March ";
              daysinmonth = 31;
              break;
     
            case 4:
     
              monthname="April ";
              daysinmonth = 30;
              break;
     
            case 5:
     
              monthname="May ";
              daysinmonth = 31;
              break;
     
            case 6:
     
              monthname="June ";
              daysinmonth = 30;
              break;
     
            case 7:
     
              monthname="July ";
              daysinmonth = 31;
              break;
     
            case 8:
     
              monthname="Aug ";
              daysinmonth = 31;
              break;
     
            case 9:
     
              monthname="Sept ";
              daysinmonth = 30;
              break;
     
            case 10:
     
              monthname="Oct ";
              daysinmonth = 31;
              break;
     
            case 11:
     
              monthname="Nov ";
              daysinmonth = 30;
              break;
     
            case 12:
     
              monthname="Dec ";
              daysinmonth = 31;
              break;
     
            default:
     
              System.out.println("Invalid data");
              break;
     
          }
     
          System.out.println("");
          System.out.println("          "+monthname);
          System.out.println("");
     
          display();
     
          for(spacesforstartday=1;spacesforstartday<=startday;spacesforstartday++)
          {System.out.print("   ");}
     
          for(date=1; date<=daysinmonth; date++)
          { 
            if(startday%7 == 0 && startday != 0)
            {System.out.println();}
            if(date<10)
            {System.out.print("  "+date);}
            else
            {System.out.print(" "+date);}
            startday=startday+1;
          }
     
     
     
          startday%=7;
          System.out.println("");
          System.out.println("");
        }
     
     
     
        System.exit(0);
     
      }}

              2013
              ====
     
              Jan 
     
      S  M  T  W  T  F  S
    ---------------------
               1  2  3  4
      5  6  7  8  9 10 11
     12 13 14 15 16 17 18
     19 20 21 22 23 24 25
     26 27 28 29 30 31
     
     
              Feb 
     
      S  M  T  W  T  F  S
    ---------------------
                        1
      2  3  4  5  6  7  8
      9 10 11 12 13 14 15
     16 17 18 19 20 21 22
     23 24 25 26 27 28
     
     
              March 
     
      S  M  T  W  T  F  S
    ---------------------
                        1
      2  3  4  5  6  7  8
      9 10 11 12 13 14 15
     16 17 18 19 20 21 22
     23 24 25 26 27 28 29
     30 31
     
     
              April 
     
      S  M  T  W  T  F  S
    ---------------------
            1  2  3  4  5
      6  7  8  9 10 11 12
     13 14 15 16 17 18 19
     20 21 22 23 24 25 26
     27 28 29 30
     
     
              May 
     
      S  M  T  W  T  F  S
    ---------------------
                  1  2  3
      4  5  6  7  8  9 10
     11 12 13 14 15 16 17
     18 19 20 21 22 23 24
     25 26 27 28 29 30 31
     
     
              June 
     
      S  M  T  W  T  F  S
    ---------------------
      1  2  3  4  5  6  7
      8  9 10 11 12 13 14
     15 16 17 18 19 20 21
     22 23 24 25 26 27 28
     29 30
     
     
              July 
     
      S  M  T  W  T  F  S
    ---------------------
            1  2  3  4  5
      6  7  8  9 10 11 12
     13 14 15 16 17 18 19
     20 21 22 23 24 25 26
     27 28 29 30 31
     
     
              Aug 
     
      S  M  T  W  T  F  S
    ---------------------
                     1  2
      3  4  5  6  7  8  9
     10 11 12 13 14 15 16
     17 18 19 20 21 22 23
     24 25 26 27 28 29 30
     31
     
     
              Sept 
     
      S  M  T  W  T  F  S
    ---------------------
         1  2  3  4  5  6
      7  8  9 10 11 12 13
     14 15 16 17 18 19 20
     21 22 23 24 25 26 27
     28 29 30
     
     
              Oct 
     
      S  M  T  W  T  F  S
    ---------------------
               1  2  3  4
      5  6  7  8  9 10 11
     12 13 14 15 16 17 18
     19 20 21 22 23 24 25
     26 27 28 29 30 31
     
     
              Nov 
     
      S  M  T  W  T  F  S
    ---------------------
                        1
      2  3  4  5  6  7  8
      9 10 11 12 13 14 15
     16 17 18 19 20 21 22
     23 24 25 26 27 28 29
     30
     
     
              Dec 
     
      S  M  T  W  T  F  S
    ---------------------
         1  2  3  4  5  6
      7  8  9 10 11 12 13
     14 15 16 17 18 19 20
     21 22 23 24 25 26 27
     28 29 30 31

  8. #8
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    Default Re: Homework - Calendar Assignment

    What is the problem?
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: Homework - Calendar Assignment

    January 1st of this year lands on a Tuesday, yet the program assigns it to Wednesday and it throws off the whole calendar.

  10. #10
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    Default Re: Homework - Calendar Assignment

    How does the program decide what day January 1 is on and use that to do the spacing to put the 1 in the right spot?
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: Homework - Calendar Assignment

    This code gets the variable that assigns the day of the first of January

        startdaystr = JOptionPane.showInputDialog("What is the day of January 1? (S-1 M-2 T-3 W-4 T-5 F-6 S-7)");
        startday = Integer.parseInt(startdaystr);



    This code handles the spacing and the first of the month.

    for(spacesforstartday=1;spacesforstartday<=startday;spacesforstartday++)
          {System.out.print("   ");}
     
          for(date=1; date<=daysinmonth; date++)
          { 
            if(startday%7 == 0 && startday != 0)
            {System.out.println();}
            if(date<10)
            {System.out.print("  "+date);}
            else
            {System.out.print(" "+date);}
            startday=startday+1;
          }
     
     
     
          startday%=7;
          System.out.println("");
          System.out.println("");
        }

  12. #12
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    Default Re: Homework - Calendar Assignment

    Did you play computer with the code to see what it is doing? You know that it prints extra spaces to push the first 1 to the right 1 day. Look at the code to see why.
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: Homework - Calendar Assignment

    I've messed with the code for quite a while, I can't seem to get it to work correctly without pushing all of the other dates onto a new line.

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    Default Re: Homework - Calendar Assignment

    Look at what value is put in the startday variable and how it is computed, how the loop control variable starts at 1 vs 0 and the loop terminating test uses <= vs <

    Consider this: Sunday means 0 leading spaces
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: Homework - Calendar Assignment

    The first two variables that you mentioned were necessary, when I altered them the problem worsened.

    Nothing that I'm trying is helping to correct the issue. Do you have any suggested fixed?

  16. #16
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    Default Re: Homework - Calendar Assignment

    DId you Consider this: The first day of Sunday means 0 leading spaces

    --- Update ---

    Also posted at Calendar Assignment - Dev Shed
    If you don't understand my answer, don't ignore it, ask a question.

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