Write a program to display the sign of the Zodiac corresponding to a birth date entered through the keyboard.
Output of Above Java Program
January 17, 2012
Enter the year: 1990
Enter the month number January is 1, December is 12: 8
Enter the day in the month: 23
August 23, 1990 is in the sign of Virgo
Do you want to try another date(Enter Y or N)?
y
Enter the year: 1992
Enter the month number January is 1, December is 12: 3
Enter the day in the month: 30
March 30, 1992 is in the sign of Aries
Do you want to try another date(Enter Y or N)?
n
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.GregorianCalendar;
import java.text.DateFormat;
public class ZodiacSigns {
public static void main(String[] args) {
System.out.println(df.format(calendar.getTime()));
int day = 0;
int month = 0;
int year = 0;
while(true) {
// Read in a date
System.out.print("Enter the year: ");
year = readInt();
while(true){
System.out.print("Enter the month number January is 1, December is 12: ");
month = readInt();
if(validMonth(--month)) // Change month to zero-based and validate
break;
}
while(true) {
System.out.print("Enter the day in the month: ");
day = readInt();
if(validDay(day, month, year)) { // Verify date is valid for month and year
break;
}
}
// determine the sign
calendar.set(year, month,day); // Set the calendar to the date entered
// Match the year for the sign start dates
for(int i = 0 ; i < signStartDates.length ; ++i)
signStartDates[i].set(GregorianCalendar.YEAR, year);
for(int i = 0 ; i < signStartDates.length ; ++i)
if(calendar.after(signStartDates[i]) && calendar.before(signStartDates[(i+1)%signStartDates.length])) {
System.out.println(df.format(calendar.getTime()) + " is in the sign of " + signs[i]);
break;
}
// Try another date?
System.out.println("Do you want to try another date(Enter Y or N)?");
if(!yes()) {
break;
}
}
}
// Validate the month value
private static boolean validMonth(int month) {
if(month >= 0 && month <= 11)
return true;
else
System.out.println("The month value must be from 1 to 12. Try again.");
return false;
}
// Validate the day value for the month and year
private static boolean validDay(int day, int month, int year) {
/* A valid day must be:
- between 1 and 31
- less than 31 when the month is April, June, September, or November
- less than 29 when the month is February and it is not a leap year
- less than 30 when the month is February and it is a leap year
*/
if (day < 0 || day > 31) {
System.out.println("Day values must be between 1 and 31. Try again.");
return false;
}
if(day > 30 && (month == 3 || month == 5 || month == 8 || month == 10)) {
System.out.println("Day values must be less than 31 when the month" + " is " + MONTH_NAMES[month] + ". Try again.");
return false;
}
if(day > 28 && month == 1 && !calendar.isLeapYear(year)) {
System.out.println(year + " is not a leap year so day values must be less than 29. Try again.");
return false;
}
if(day > 29 && month == 1 && calendar.isLeapYear(year)) {
return false;
}
return true;
}
// Reads an integer from the keyboard
private static int readInt() {
int value = 0;
while(true) {
try {
value = Integer.parseInt(in.readLine().trim());
return value;
}catch(NumberFormatException e) {
System.out.println("Invalid input. Try again.");
} catch(IOException e){
System.out.println("Error reading for the keyboard." + e.getMessage());
}
}
}
private static boolean yes() {
String str = null;
while(true) {
try {
str = in.readLine().trim();
} catch(IOException e) {
System.out.println("Error reading for the keyboard." + e.getMessage());
}
if(str.equalsIgnoreCase("Y")) {
return true;
} else if(str.equalsIgnoreCase("N")) {
break;
} else {
System.out.print("Invalid input. Try again. Enter Y or N: ");
}
}
return false;
}
private static BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); // Keyboard input
// Names for Zodiac signs and start dates. Remember - months start at zero.
private static String[] signs = {"Aquarius", "Pisces", "Aries" , "Taurus",
"Gemini" , "Cancer", "Leo" , "Virgo",
"Libra" ,"Scorpio", "Sagittarius", "Capricorn" };
private static GregorianCalendar[] signStartDates = {
new GregorianCalendar(2002, 0, 20), // Aquarius start date
new GregorianCalendar(2002, 1, 19), // Pisces start date
new GregorianCalendar(2002, 2, 21), // Aries start date
new GregorianCalendar(2002, 3, 20), // Taurus start date
new GregorianCalendar(2002, 4, 21), // Gemini start date
new GregorianCalendar(2002, 5, 21), // Cancer start date
new GregorianCalendar(2002, 6, 23), // Leo start date
new GregorianCalendar(2002, 7, 23), // Virgo start date
new GregorianCalendar(2002, 8, 23), // Libra start date
new GregorianCalendar(2002, 9, 23), // Scorpio start date
new GregorianCalendar(2002, 10, 22), // Sagittarius start date
new GregorianCalendar(2002, 11, 22), // Capricorn start date
};
private static GregorianCalendar calendar = new GregorianCalendar();
// Array defining the names of the months.
// Note that DateFormatSymbols class defines an instance method, getMonths(),
// that will return exactly this array of String objects.
private static final String[] MONTH_NAMES = {
"January" , "February", "March" , "April",
"May" , "June" , "July" , "August",
"September", "October" , "November", "December" };
// Date formatter for displaying dates
private static DateFormat df = DateFormat.getDateInstance(DateFormat.LONG);
}
Output of Above Java Program
January 17, 2012
Enter the year: 1990
Enter the month number January is 1, December is 12: 8
Enter the day in the month: 23
August 23, 1990 is in the sign of Virgo
Do you want to try another date(Enter Y or N)?
y
Enter the year: 1992
Enter the month number January is 1, December is 12: 3
Enter the day in the month: 30
March 30, 1992 is in the sign of Aries
Do you want to try another date(Enter Y or N)?
n
