I am following "The Art and Science of Java" book and it shows how to calculate a leap year. The book uses ACM Java Task Force's library.
Here is the code the books uses:
import acm.program.*;
public class LeapYear extends ConsoleProgram {
public void run()
{
println("This program calculates leap year.");
int year = readInt("Enter the year: ");
boolean isLeapYear = ((year % 4 == 0) && (year % 100 != 0) || (year % 400 == 0));
if (isLeapYear)
{
println(year + " is a leap year.");
} else
println(year + " is not a leap year.");
}
}
Now, this is how I calculated the leap year.
import acm.program.*;
public class LeapYear extends ConsoleProgram {
public void run()
{
println("This program calculates leap year.");
int year = readInt("Enter the year: ");
if ((year % 4 == 0) && year % 100 != 0)
{
println(year + " is a leap year.");
}
else if ((year % 4 == 0) && (year % 100 == 0) && (year % 400 == 0))
{
println(year + " is a leap year.");
}
else
{
println(year + " is not a leap year.");
}
}
}
Is there anything wrong with my code or should i use the one provided by the book ?
EDIT :: Both of the above code works fine, What i want to ask is which code is the best way to calculate the leap year.
The correct implementation is:
public static boolean isLeapYear(int year) {
Calendar cal = Calendar.getInstance();
cal.set(Calendar.YEAR, year);
return cal.getActualMaximum(Calendar.DAY_OF_YEAR) > 365;
}
But if you are going to reinvent this wheel then:
public static boolean isLeapYear(int year) {
if (year % 4 != 0) {
return false;
} else if (year % 400 == 0) {
return true;
} else if (year % 100 == 0) {
return false;
} else {
return true;
}
}