Java Code Example: check leap year in if else statement

A normal year has 365 days. Every four years, however, there is a leap year with 366 days. This is because the earth does not need exactly 365 days to travel once around the sun, but about a quarter day more. So a year has one day more every 4 years.

So that the calculation is correct, there is no leap year every 100 years. Nevertheless, every four hundred years a leap year takes place. This concerns the years 2000, 2400 etc.

class CheckLeapYearExample {
    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;
        }
    }

    public static void main(String[] args) {
        int year = 2020;

        if (isLeapYear(year)) {
            System.out.println(year + " is a leap year");
        } else {
            System.out.println(year + " is not a leap year");
        }
    }
}
Output
2020 is a leap year