finished exercise 29

Author: Jonathan-Birkey

src/com/github/jonathanbirkey/chapter05/Exercise29.java

@@ -0,0 +1,140 @@
+/**
+ * @author : Jonathan Birkey
+ * @mailto : [email protected]
+ * @created : 28Feb2024
+ *     <p>(Display calendars) Write a program that prompts the user to enter the year and first day
+ *     of the year and displays the calendar table for the year on the console. For example, if the
+ *     user entered the year 2013, and 2 for Tuesday, January 1, 2013, your program should display
+ *     the calendar for each month in the year, as follows:
+ *     <p>January 2013
+ *     <p>---------------------------
+ *     <p>Sun Mon Tue Wed Thu Fri Sat
+ *     <p>1 2 3 4 5
+ *     <p>6 7 8 9 10 11 12
+ *     <p>13 14 15 16 17 18 19
+ *     <p>20 21 22 23 24 25 26
+ *     <p>27 28 29 30 31
+ *     <p>
+ *     <p>...
+ *     <p>
+ *     <p>December 2013
+ *     <p>---------------------------
+ *     <p>Sun Mon Tue Wed Thu Fri Sat
+ *     <p>1 2 3 4 5 6 7
+ *     <p>8 9 10 11 12 13 14
+ *     <p>15 16 17 18 19 20 21
+ *     <p>22 23 24 25 26 27 28
+ *     <p>29 30 31
+ */
+package com.github.jonathanbirkey.chapter05;
+
+import java.util.Scanner;
+
+public class Exercise29 {
+  public static void main(String[] args) {
+    Scanner input = new Scanner(System.in);
+    System.out.print("Enter year: (e.g., 2012): ");
+    int year = input.nextInt();
+    System.out.print("Enter first day of year (0 - Saturday, 1 - Sunday, 2 - Monday, etc): ");
+    int firstDay = input.nextInt();
+    input.close();
+
+    int daysInMonth = 0;
+    String monthHeader;
+
+    for (int month = 1; month <= 12; month++) {
+      if (month == 1
+          || month == 3
+          || month == 5
+          || month == 7
+          || month == 8
+          || month == 10
+          || month == 12) {
+        daysInMonth = 31;
+      } else if (month == 4 || month == 6 || month == 9 || month == 11) {
+        daysInMonth = 30;
+      } else {
+        if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)) {
+          daysInMonth = 29;
+        } else {
+          daysInMonth = 28;
+        }
+      }
+      switch (month) {
+        case 1:
+          monthHeader = "       January " + year;
+          break;
+        case 2:
+          monthHeader = "       Febuary " + year;
+          break;
+        case 3:
+          monthHeader = "        March " + year;
+          break;
+        case 4:
+          monthHeader = "        April " + year;
+          break;
+        case 5:
+          monthHeader = "         May " + year;
+          break;
+        case 6:
+          monthHeader = "         June " + year;
+          break;
+        case 7:
+          monthHeader = "         July " + year;
+          break;
+        case 8:
+          monthHeader = "        August " + year;
+          break;
+        case 9:
+          monthHeader = "      September " + year;
+          break;
+        case 10:
+          monthHeader = "       October " + year;
+          break;
+        case 11:
+          monthHeader = "       November " + year;
+          break;
+        case 12:
+          monthHeader = "       December " + year;
+          break;
+        default:
+          monthHeader = "Invalid";
+      }
+
+      System.out.printf(
+          "%s\n---------------------------\nSun Mon Tue Wed Thu Fri Sat\n", monthHeader);
+
+      int dayShift = 0;
+      if (firstDay > 0) {
+        dayShift = firstDay - 1;
+      } else {
+        dayShift = firstDay + 6;
+      }
+
+      for (int i = 0; i < dayShift; i++) {
+        System.out.print("    ");
+      }
+
+      for (int date = 1; date <= daysInMonth; date++) {
+        if (dayShift == 6) {
+          if (date < 10) {
+            System.out.printf("  %d\n", date);
+          } else {
+            System.out.printf(" %d\n", date);
+          }
+          dayShift = 0;
+        } else {
+          if (date < 10) {
+            System.out.printf("  %d ", date);
+          } else {
+            System.out.printf(" %d ", date);
+          }
+          dayShift++;
+        }
+      }
+      System.out.print("\n\n");
+
+      firstDay = (firstDay + daysInMonth) % 7;
+    }
+  }
+}