check if leap year java

In this tutorial, we will learn how to check if leap year java. A leap year is a special year which has 1 day extra. This normal years have 365 days, however a leap year has 366 days. A leap year comes every 4 years.

Here is a Java Program to check Leap year, A leap year has 366 days, instead of 365. To check if leap year java is a leap year or not first we have to find out the possible ways of checking a leap year mathematically. The following conditions have to be fulfilled:

The year is a leap year if it has 366 days.
It is not if it has 365 days.
The year is evenly divisible by 400, then check for step 1, else move to step 2.
If it is evenly divisible by 100, check for step 3, else move to step 1.
The year is evenly divided by 4, check for step 4, else move to step 2.

Steps to Check Leap Year

Take an integer variable as input for the year.
Assign a particular value to the variable.
We first check if the year is divisible by 4, but not 100, simply print the output as The year is a leap year.
If the input is completely divisible by 400, simply print the same output.
Else, we print ‘The year is not a leap year’.

Java Code to Check Leap Year by Giving Input

import java.util.Scanner;
public class LeapYear {
public static void main(String[] args) {
int year;
Scanner scan = new Scanner(System.in);
System.out.println("Enter a year to check if it is a leap year:");
year = scan.nextInt();
scan.close();
boolean Leap = false;
if(year % 4 == 0)
{
if( year % 100 == 0)
{
if ( year % 400 == 0)
Leap = true;
else
Leap = false;
}
else
Leap = true;
}
else {
Leap = false;
}
if(Leap==true)
System.out.println(year + " is a Leap Year.");
else
System.out.println(year + " is not a Leap Year.");
}
}

Learn Scanner Class in Java

The output of the program will be:

Enter a year to check if it is a leap year: 2020
2020 is a leap year

Check Leap Year

Algorithm

Start
Declare a variable let’s say a year.
Initialize it.
Check for the conditions.
If the condition satisfies then it is a leap year else not.
Display the result.
Stop.

This is the whole elaborated version of how to understand the algorithm. To reduce the complexity of the program, we can also write is as following:

Code :

public class DeveloperHelps {
public static void main(String[] args)
{
//year to leap year or not
int year = 2020;
System.out.println();        
if((year % 400 == 0) || ((year % 4 == 0) && (year % 100 != 0)))
System.out.println(year + " is a leap year");
else
System.out.println(year + " is not a leap year");
System.out.println();
}
}

Output :

2020 is a leap year.

Check Leap Year using Conditional Operators

Algorithm

Start
Declare a variable let’s say a year.
Initialize it.
Use a ternary operator to check whether the given year is a leap year or not.
Call a method in the condition section of the ternary operator to check the same.
Return true if the year is a multiple of 400.
Else if the year is a multiple of 100, return false.
Else if the year is a multiple of 4 then it is a leap year and return true. Else return false.
Stop.

Code :

//Java Program to check whether the given year is a leap year or not
import java.util.Scanner;

public class CheckYear
{
static boolean checkLeapYear(int year)
    {
        // If a year is multiple of 400, then it is a leap year
        if (year % 400 == 0)
            return true;
     
        // Else If a year is multiple of 100, then it is not a leap year
        if (year % 100 == 0)
            return false;
     
        // Else If a year is multiple of 4, then it is a leap year
        if (year % 4 == 0)
            return true;
        return false;
    }
         
    // Driver method
     public static void main(String []args)
     {
        Scanner sc=new Scanner(System.in);
        int year;   //Year Declaration
        System.out.println("Enter the year");
        year=sc.nextInt();   //Year Initialization
        
        //Ternary Operator to check
        System.out.println( checkLeapYear(2000)? "Leap Year" :
                           "Not a Leap Year" );    
     }
     
}