adding the date class files

lectures/03_classes_I/date.cpp

@@ -0,0 +1,86 @@
+// File:    date.cpp
+// Purpose: Implementation file for the Date class.
+
+#include <iostream>
+#include "date.h"
+
+// array to figure out the number of days, it's used by the auxiliary function daysInMonth
+const int DaysInMonth[13] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+
+Date::Date() {	//default constructor
+  day = 1;
+  month = 1;
+  year = 1900;
+}
+
+Date::Date(int aMonth, int aDay, int aYear) { // construct from month, day, & year
+  month = aMonth;
+  day = aDay;
+  year = aYear;
+}
+
+
+int Date::getDay() const {
+  return day;
+}
+
+int Date::getMonth() const {
+  return month;
+}
+	
+int Date::getYear() const {
+  return year;
+}
+
+void Date::setDay(int d) {
+  day = d;
+}
+
+void Date::setMonth(int m) {
+  month = m;
+}
+
+void Date::setYear(int y) {
+  year = y; 
+}
+
+void Date::increment() {
+  if (!isLastDayInMonth()) {
+    day++; 
+  } else {
+    day = 1;
+    if (month == 12) {  // December
+      month = 1;
+      year++;
+    } else {
+      month++;
+    }
+  }
+}
+
+bool Date::isEqual(const Date& date2) const {
+  return day == date2.day && month == date2.month && year == date2.year;
+}
+
+bool Date::isLeapYear() const {
+  return (year%4 ==0 && year % 100 != 0) || year%400 == 0;
+}
+
+int Date::lastDayInMonth() const {
+  if (month == 2 && isLeapYear())
+    return 29;
+  else
+    return DaysInMonth[ month ];    
+}
+
+bool Date::isLastDayInMonth() const {
+  return day == lastDayInMonth();   // uses member function
+}
+
+void Date::print() const {
+  std::cout << month << "/" << day << "/" << year;
+}
+
+bool sameDay(const Date& date1, const Date& date2) {
+  return date1.getDay() == date2.getDay() && date1.getMonth() == date2.getMonth();
+}