A leap year is exactly divisible by 4 except for century years (years ending with 00). The century year is a leap year only if it is perfectly divisible by 400.
Example: Java Program to Check a Leap Year
public class Main {
public static void main(String[] args) {
// year to be checked
int year = 1900;
boolean leap = false;
// if the year is divided by 4
if (year % 4 == 0) {
// if the year is century
if (year % 100 == 0) {
// if year is divided by 400
// then it is a leap year
if (year % 400 == 0)
leap = true;
else
leap = false;
}
// if the year is not century
else
leap = true;
}
else
leap = false;
if (leap)
System.out.println(year + " is a leap year.");
else
System.out.println(year + " is not a leap year.");
}
}
Output
1900 is not a leap year.
In the above example, we are checking if the year 1900 is a leap year or not. Since 1900 is a century year (ending with 00), it should be divisible by both 4 and 400 to be a leap year.
However, 1900 is not divisible by 400. Hence, it is not a leap year.
Now, let's change the year to 2012. The output will be
2012 is a leap year.
Here, 2012 is not a century year. Hence, to be a leap year, it needs to be divisible by only 4.
Since 2012 is divisible by 4, it is a leap year.