pCal.java

/* This code is my own work. I did not get any help from any online source 
such as chegg.com; from a classmate, or any other person other than the instructor 
or TA for this course. I understand that getting outside help from this course 
other than from the instructor or TA will result in a grade of 0 in this 
assignment and other disciplinary actions for academic dishonesty.

# Name : Cristian Z

# Class: CSET 1200

# Instructor: Dr. Jared Oluoch

# Programming Assignment: 5

# Problem: 1

# Date: 10/06/21 

# Summary: months from march to august with total days

#code based from book chapter 6

# 

*/

import java.util.Scanner;
public class pCal {
	public static void main(String[] args) {
	Scanner input = new Scanner(System.in);
		
	// Prompt the user to enter year
	System.out.print("Enter full year (ex:1999): ");
	int year = input.nextInt();
	
	// Prompt the user to enter month
	System.out.print("Enter month as a number between 1 and 12: ");
	int month = input.nextInt();
	
	// Print calendar for the month of the year
	printMonth(year, month);
	}

	//Print the calendar for a month in a specific year
	public static void printMonth(int year, int month) {
	// Print the headings of the calendar
	printMonthTitle(year, month);

	// Print the body of the calendar
	printMonthBody(year, month);
	}
	
	//Print the month title Jan 2000
	public static void printMonthTitle(int year, int month) {
		System.out.println(" " + getMonthName(month) + " " + year);
		System.out.println("−−−−−−−−−−−−−−−−−−−−−−−−−−−−−");
		System.out.println(" Sun Mon Tue Wed Thu Fri Sat");
	}
	
	//Get the month 
	public static String getMonthName(int month) {
	String monthName = "";
		switch (month) {
			case 1: monthName = "January"; break;
			case 2: monthName = "February"; break;
			case 3: monthName = "March"; break;
			case 4: monthName = "April"; break;
			case 5: monthName = "May"; break;
			case 6: monthName = "June"; break;
			case 7: monthName = "July"; break;
			case 8: monthName = "August"; break;
			case 9: monthName = "September"; break;
			case 10: monthName = "October"; break;
			case 11: monthName = "November"; break;
			case 12: monthName = "December";
	}
	//print month's body
	return monthName;
	}
	
	public static void printMonthBody(int year, int month) {
		// Get start day of the week for the first date in the month
		int startDay = getStartDay(year, month);
	
		// Get number of days in the month
		int numberOfDaysInMonth = getNumberOfDaysInMonth(year, month);
	
		// Pad space before the first day of the month
		int i = 0;
		for (i = 0; i < startDay; i++)
			System.out.print(" ");
	
			for (i = 1; i <= numberOfDaysInMonth; i++) {
				System.out.printf("%4d", i);
	
			if ((i + startDay) % 7 == 0)
				System.out.println();
	} 
}
	// Get the start day of month/1/year 
	public static int getStartDay(int year, int month) {
		final int START_DAY_FOR_JAN_1_1800 = 3;
	
		// Get total number of days from 1/1/1800 to month/1/year
		int totalNumberOfDays = 
		{
			int total = 0;
	
		// Get the total days from 1800 to 1/1/year
		for (int i = 1800; i < year; i++)
			if (isLeapYear(i))
				total = total + 366;
			else
				total = total + 365;

	// Add days from Jan to the month prior to the calendar month
	for (int i = 1; i < month; i++)
		total = total + getNumberOfDaysInMonth(year, i);}
 
		// Return the start day for month/1/year
		return (totalNumberOfDays + START_DAY_FOR_JAN_1_1800) % 7;
 }
	// Get the total number of days since January 1, 1800
	public static int getTotalNumberOfDays(int year, int month) {
		int total = 0;
	
		// Get the total days from 1800 to 1/1/year
		for (int i = 1800; i < year; i++)
			if (isLeapYear(i))
				total = total + 366;
			else
				total = total + 365;

	// Add days from Jan to the month prior to the calendar month
	for (int i = 1; i < month; i++)
		total = total + getNumberOfDaysInMonth(year, i);

	return total;
 }

	// Get the number of days in a month 
	public static int getNumberOfDaysInMonth(int year, int month) {
		if (month == 1 || month == 3 || month == 5 || month == 7 || 
		month == 8 || month == 10 || month == 12)
	return 31;

	if (month == 4 || month == 6 || month == 9 || month == 11)
	return 30;

	if (month == 2) return isLeapYear(year) ? 29 : 28;
	
	return 0; // If month is incorrect
	}

	// Determine if it is a leap year 
	public static boolean isLeapYear(int year) {
	return year % 400 == 0 || (year % 4 == 0 && year % 100 != 0);
	}
}