Thread: Leap year program

I am keep getting semantic error

Can you post more info about this error?
What happens when you execute the program?
If the output is wrong, please explain what is wrong and what you want it to be.

Why do you do the following:
daysInMonth = 29;

For what month is that true?

daysInMonth = 29
is for February. If an user inputs a date like 2/29/2010. Then, the program compares the decide whether there is 29th day on February of 2010. Since there is no such date apprently, the program should say "invalid," but my program is keep saying valid. Also, if I enter the 5/32/2010, the program says the date is valid as well which is not right.

Can you show the console for when you execute your program?
I don't see how your code will allow the user to enter this value: 5/32/2010

When printing out error an error message you should show the value this is incorrect in addition to saying its invalid. For example:
System.out.println("not valid");
should say what(yr, day, month) is invalid and show invalid value.

daysInMonth = 29;
Is this for ALL the months in a leap year?

use switch code..

refer to this.. a simple calendar

public class MyCalendar
{
    private final int newYear1901=2;//Jan. 1, 1901, Tue(2)
    private int month;
    private int year;
 
    public MyCalendar(int month, int year)
    {
        this.month=month;
        this.year=year;
    }
 
    public MyCalendar()
    {
        this(1,2010);
    }
 
    public int newYearDay(int year)
    {
        int elapseYear=year-1901;
        int countLeapYear=(elapseYear)/4;
        return(newYear1901+elapseYear+countLeapYear)%7;
    }
 
    public boolean isLeapYear(int year)
    {
        return (year%4)==0;
    }
 
    public int monthDays(int month, int year)
    {
        int days=-1;
        switch(month)
        {
            case 1: case 3: case 5: case 7: case 8: case 10: case 12:
            days=31;break;
            case 4: case 6: case 9: case 11:
            days=30;break;
            case 2:
            days=(isLeapYear(year))?29:28;
        }
 
        return days;
    }
 
    public int firstDayMonth(int month, int year)
    {
        int newYear=newYearDay(year);
        int totalDays=0;
        for(int i=1;i<month;i++)
        {
            totalDays+=monthDays(i,year);
        }
        return(newYear+totalDays)%7;
    }
 
    public String monthName(int month)
    {
        String name="";
        switch(month)
        {
            case 1:name="January"; break;
            case 2:name="February"; break;
            case 3:name="March"; break;
            case 4:name="April"; break;
            case 5:name="May"; break;
            case 6:name="June"; break;
            case 7:name="July"; break;
            case 8:name="August"; break;
            case 9:name="September"; break;
            case 10:name="Ocotber"; break;
            case 11:name="November"; break;
            case 12:name="December"; break;
        }
        return name;
    }
 
    public void displayChart()
    {
        String[]dayNames={"SUN","MON","TUE","WED","THU","FRI","SAT"};
        System.out.printf("\n\n%s\t%d\n", monthName(month),year);
    System.out.println("----------------------------------------------------");
 
        for(String d:dayNames)
        System.out.print(d+"\t");
        System.out.println("\n----------------------------------------------------");  
 
        int i=0;
        for(;i<firstDayMonth(month,year);i++)
        System.out.print("\t");
 
        for(int j=1;(i<42 && j<=monthDays(month,year));i++,j++)
        {
            if((i%7)==0)
            System.out.printf("\n%3d\t",j);
            else
            System.out.printf("%3d\t",j);
 
        }
        System.out.println("\n----------------------------------------------------");  
 
    }
 
    public static void main(String[]args)
    {
        try
        {
            System.out.print("YEAR: ");
            int year=new java.util.Scanner(System.in).nextInt();
            System.out.print("MONTH: ");
            int month=new java.util.Scanner(System.in).nextInt();
            MyCalendar m= new MyCalendar(month,year);
 
            m.displayChart();
        }
        catch(Exception e)
        {
            System.out.println("INVALID INPUT..Enter Number");
                System.out.print("YEAR: ");
            int year=new java.util.Scanner(System.in).nextInt();
            System.out.print("MONTH: ");
            int month=new java.util.Scanner(System.in).nextInt();
            MyCalendar m= new MyCalendar(month,year);
 
            m.displayChart();
        }
    }
}//end of class

i hope it helps..