Thread: Advancing day w/ if/else & switch statement

I have a project due Monday for my Intro Java class and I really need to do well on it! I need to write a MyDate class that has 3 integers representing month, day & year. in it, I need a MyDate method, and adavceByOneDay method. In my tester class, I need to run scanner input and propts/reads month, day, year inputs. It also needs to print the date before and after it has been advanced by a day. I need to take into account month/year rollover, and leap years. I think using the gregorian calendar may be easier to set up the date, but the section we've been working on is "if/else" and "switch" statements. I think my part of my problem is that I don't fully understand how to relate the tester class with the main class. Anyhelp is greatly appreciated!

public class MyDate {
	public int month, day, year;
	public MyDate(int month , int day, int year) {
		MyDate date = new MyDate(month, day, year);
	}
 
	public boolean advanceByOneDay(){
		boolean isAdvanced = true;
		if(day+1> daysInMonth())
		{
			if(month+1 > 12)
			{	
			month = 1;
			day = 1;
			year++;
			}
			else
			{
			month++;
			day = 1;		
			}
		}
		else
		{
			day++;
		}
		return isAdvanced;
}	
 
 
	public static String getMonthInString(int n) {
		String result = "";
		switch(n) {
		case 1: result = "January"; break;
		case 2: result = "Febuary"; break;
		case 3: result = "March"; break;
		case 4: result = "April"; break;
		case 5: result = "May"; break;
		case 6: result = "June"; break;
		case 7: result = "July"; break;
		case 8: result = "August"; break;
		case 9: result = "September"; break;
		case 10: result = "October"; break;
		case 11: result = "November"; break;
		case 12: result = "December"; break;
		default: result = "Error"; //break;
		}
		return result;		
	}
 
	private boolean isLeapYear(){
		boolean leap = false;
		if (year % 4 == 0) 
		{
			if (year % 100 == 0)
			{
				if (year % 400 == 0)
				{
					leap = true;
				}
				else 
					leap = false;
			}
		}
		return leap;
	}
 
 
 
 
	private int daysInMonth() {
		switch (month){
		case 1:day = 31;break;
		case 2:if (isLeapYear())
				day = 29;
				else
					day = 28;break;
		case 3:day = 31;break;
		case 4:day = 30;break;
		case 5:day = 31;break;
		case 6:day = 30;break;
		case 7:day = 31;break;
		case 8:day = 31;break;
		case 9:day = 30;break;
		case 10:day = 31;break;
		case 11:day = 30;break;
		case 12:day = 31;break;
		default:
		if ((month < 1)||(month > 12));
 
 
		}
		return day;
	}

import java.util.Scanner;
 
public class MyDateTester {
	public int month, day, year;
 
 
 
 
	public static void main(String[] args) {
		int month;
		int day;
		int year;
 
		Scanner input = new Scanner(System.in);
		System.out.println("This program was written by Robert Read");
		System.out.println("This program will allow you to input month, day, and year in digits, advance it by one day and print both dates in proper format.");
		System.out.println("Enter the month by it numerical value (1 for January, 2 for Febuary, etc): ");
		month = input.nextInt();
		System.out.println("Enter the Day (between 1-31 depending on the month): ");
		day = input.nextInt();
		System.out.println("Enter the four digit year; ");
		year = input.nextInt();	
 
		return(isAdvanced);
}
}

Hi rbread80,
in tester class, you set from standard input 3 integer: day, month and year.
But you don't use your class MyDate.

Maybe the solution is:
put in your tester class this code:

MyDate myDate = new MyDate(month,day,year);
return (myDate.advanceByOneDay);

2 things I don't understand:

1) the constructor of MyClass
2) function advanceByOneDay returns ever TRUE
so what do u want test if the result is ever TRUE?

Tell me!

I've changed it some, but here is my new advanceByOneDay method

public String advanceByOneDay(){
		/**
		* advances date by one day
		**/
 
		String result= " ";
 
		if(day+1> daysInMonth())
		{
		if(month+1 > 12)
		{ 
		month = 1;
		day = 1;
		year++;
		}
		else
		{
		month++;
		day = 1; 
		}
		}
		else
		{
		day++;
		}
		return result;
		}

honestly, i'm not too sure about my constructor too. if you have any suggestions, let me know!
Right now, it looks like my advanceByOneDay and isLeapYear methods aren't working right. I think it may be that advanceByOneDay doesn't read the scanner input right, and isLeapYear works, except that it won't respond with the correct days in a leap year.
thanks for the reply!
brandon

After my tweaking, this is my entire updated code:

public class MyDate {
 
	public int month, day, year;
 
 
	public MyDate(int month , int day, int year) {
 
		this.month = month;
		this.day = day;
		this.year = year;
	}
 
	int daysInMonth() {
		/**
		 * Gives the number of days in a year
		 **/
 
		switch (month){
		case 1:day = 31;break;
		case 2:if (isLeapYear())
				day = 29;
				else
					day = 28;break;
		case 3:day = 31;break;
		case 4:day = 30;break;
		case 5:day = 31;break;
		case 6:day = 30;break;
		case 7:day = 31;break;
		case 8:day = 31;break;
		case 9:day = 30;break;
		case 10:day = 31;break;
		case 11:day = 30;break;
		case 12:day = 31;break;
		default:
		if ((month < 1)||(month > 12));
 
		}
		return day;
	}
 
	public String advanceByOneDay(){
		/**
		* advances date by one day
		**/
 
		String result= " ";
 
		if(day+1> daysInMonth())
		{
		if(month+1 > 12)
		{ 
		month = 1;
		day = 1;
		year++;
		}
		else
		{
		month++;
		day = 1; 
		}
		}
		else
		{
		day++;
		}
		return result;
		} 
 
	private boolean isLeapYear(){
		/**
		 * 	Decides if year is leap year.
		 **/
		boolean leap = false;
		if (year % 4 == 0) 
		{
			if (year % 100 == 0)
			{
				if (year % 400 == 0)
				{
					leap = true;
				}
				else 
					leap = false;
			}
		}
		return leap;
	}
 
 
	public static String getMonthInString(int month, int day, int year) {
		/**
		 * changes input numerical month to written month
		 **/
 
		String result = " ";		
		switch(month) {
		case 1: result = "January"; break;
		case 2: result = "February"; break;
		case 3: result = "March"; break;
		case 4: result = "April"; break;
		case 5: result = "May"; break;
		case 6: result = "June"; break;
		case 7: result = "July"; break;
		case 8: result = "August"; break;
		case 9: result = "September"; break;
		case 10: result = "October"; break;
		case 11: result = "November"; break;
		case 12: result = "December"; break;
		default: result = "Error"; //break;
		}
		return result;		
 
}	
 
 
 
 
 
	/*
	public String toString1(){		
		return getMonthInString(day, day, day);
	}
	*/
 
	public int getMonth() {return month;}
	public int getDay() {return day;}
	public int getYear() {return year;}
	public void setMonth(int month){this.month = month;}
	public void SetDay(int day){this.day = day;}
	public void setSalary(int year) {this.year = year;}
 
}

import java.util.Scanner;
 
 
public class MyDateTester {
		public static int month, day, year;
 
 
	public static void main(String[] args) {
		MyDate e = new MyDate(month, day, year);
 
 
 
		Scanner input = new Scanner(System.in);
 
		System.out.println("This program was written by Robert Read");
		System.out.println("This program will allow you to input month, day, and year in digits, advance it by one day and print both dates in proper format.");
		System.out.println("Enter the month by it numerical value (1 for January, 2 for February, etc): ");
		int month= input.nextInt();
		System.out.println("Enter the Day (between 1-31 depending on the month): ");
		int day= input.nextInt();		
		System.out.println("Enter the four digit year; ");
		int year= input.nextInt();			
 
 
 
		System.out.print(e.getMonthInString(month, day, year) + " " + e.day + ", " + e.year);
 
		System.out.print(e.daysInMonth());
 
		//System.out.println(e.advanceByOneDay(month, day, year) + " " + MyDate.getMonthInString(month, day, year) + " " + e.getDay() + ", " + e.getYear());
 
 
		//advanceByOneDay does not respond by itself
		//isLeapYear not working?
	}
 
}