Leap year and next leap year java

Question

I am trying to find the next leap year. I have the first leap year. What and where should I code? I know I need a print statement somewhere stating "is the leap year next to ("the previous leap year.)" Just not sure how to go about. for example,

input: 2016

output: 2016 is a leap year.

2020 is the leap year next to 2016.

  import java.util.Scanner;

  public class LabProgram {

  public static void main(String[] args) {

  Scanner scnr = new Scanner(System.in);
  int inputYear;
  int nextLeapYear;
  boolean isLeapYear;

  isLeapYear = false;
  inputYear = scnr.nextInt();

  if (inputYear % 4 == 0) {
        if (inputYear % 100 == 0) {
            isLeapYear = inputYear % 400 == 0;
        } else {
            isLeapYear = true;
        }
    }

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

Answer 1

Convert your year into an instance of Year or use the static Year.isLeap(x) method. You can then do all of the following:

• check if the current year is a leap year using isLeap
• add any number of years and check again whether the resulting year isLeap
• do { year = year.plusYears(4); } while (!year.isLeap()); to find the next leap year from a known leap year

java.time provides high quality libraries for time-arithmatic, which is otherwise insanely hard to get right due to the intricacies of civil time (DST, leap years, leap seconds).

Answer 2

 if (isLeapYear) {
    nextLeapYear = inputYear + 4 ;
    System.out.println(inputYear + " is a leap year.");
    System.out.println(nextLeapYear + " is next leap year.");

}    
else {
    nextLeapYear = inputYear + inputYear%4 ;
    System.out.println(inputYear + " is not a leap year.");
    System.out.println(nextLeapYear + " is next leap year.");
}

Answer 3

You can use java.time.Year .

int givenYear = 2016;
int nextLeapYear = givenYear;

if (Year.isLeap(givenYear)) {
    while (!Year.isLeap(++nextLeapYear));
    System.out.println("Is leap year.");
    System.out.println("Next one is: " + nextLeapYear);
}
else {
    System.out.println("Not a leap year.");
}

Answer 4

You can also use LocalDate to find the LeapYear 1 :

        LocalDate year2016 = LocalDate.ofYearDay(2016, 1);
        System.out.println ( "Is 2016 the leap year : " + year2016.isLeapYear());
        LocalDate nextLeapYearTest = year2016.plusYears(1);
        while(!nextLeapYearTest.isLeapYear()) {
            nextLeapYearTest = nextLeapYearTest.plusYears(1);
        }
        System.out.println ( "The next leapYear is : " + nextLeapYearTest.getYear());

Answer 5

If you love nested ifs and a hardcoded code.

public static boolean isLeapYear(int year) {

    if (year > 0 && year <= 9999) {

       if(year %4 == 0){
           if(year %100 == 0){
               if(year % 400 == 0){
                   return true;
               }
               return false;
           }
           return true;
       }
    }
    return false;
}