查找给定年份是否为闰年的Java程序

闰年有 366 天，每四年一次。每个闰年都对应于以下事实：

• 世纪年是以00结尾的年份。世纪年只有能被400整除才是闰年。
• 如果闰年能被 4 整除，则可以确定闰年（世纪年除外）。
• 一个世纪的年份应该可以被 4 和 100 整除。
• 非世纪年份只能被 4 整除。

让我们找出一年是否是闰年。

不使用扫描器类

顾名思义，这里用户一定不会选择他选择的年份。以下程序说明了确定年份是否为闰年的方法：

Java

// Java program to find a leap year
 
// Importing Classes/Files
import java.io.*;
 
// Class for leap-year dealing
public class GeeksforGeeks {
 
    // Method to check leap year
    public static void isLeapYear(int year)
    {
        // flag to take a non-leap year by default
        boolean is_leap_year = false;
 
        // If year is divisible by 4
        if (year % 4 == 0) {
 
            // To identify whether it
            // is a century year or
            // not
            if (year % 100 == 0) {
               
                // Checking if year is divisible by 400
                // therefore century leap year
                if (year % 400 == 0) {
                    is_leap_year = true;
                }
 
                else {
                    is_leap_year = false;
                }
            }
 
            // Out of if loop that is Non century year
            // but divisible by 4, therefore leap year
            is_leap_year = true;
        }
 
        // We land here when corresponding if fails
        // If year is not divisible by 4
        else
 
            // Flag dealing-  Non leap-year
            is_leap_year = false;
 
        if (!is_leap_year) {
            System.out.println(year + " : Non Leap-year");
        }
 
        else {
            System.out.println(year + " : Leap-year");
        }
    }
 
    // Main Driver Code
    public static void main(String[] args)
    {
        // Calling our function by
        // passing century year
        isLeapYear(2000);
 
        // Calling our function by
        // passing Non-century year
        isLeapYear(2002);
    }
}

输出：

2000 : Leap-year
2002 : Non Leap-year

2000 是一个世纪年，可以被 100 和 4 整除。2002 年不能被 4 整除，因此不是闰年。

使用扫描器类

在这里，用户可以灵活地输入自己选择的年份，因为在此处导入扫描仪类，其余 if-else 块也组合在一个语句中，以检查输入年份是否为闰年。以下程序说明了确定年份是否为闰年的方法：

Java

// Java program to check Leap-year
// by taking input from user
 
// Importing Classes/Files
import java.io.*;
 
// Importing Scanner Class
import java.util.Scanner;
 
// Class to check leap-year or not
public class GFG {
   
    // Driver Main code
    public static void main(String[] args)
    {
        // Considering any random year
        int year;
 
        // Taking input from user using Scanner Class
        // scn is an object made of Scanner Class
        Scanner scn = new Scanner(System.in);
        year = scn.nextInt();
 
        // 1st condition check- It is century leap year
        // 2nd condition check- It is leap year and not
        // century year
        if ((year % 400 == 0)
            || ((year % 4 == 0) && (year % 100 != 0))) {
           
            // Both conditions true- Print leap year
            System.out.println(year + " : Leap Year");
        }
 
        else {
            // Any condition fails- Print Non-leap year
            System.out.println(year + " : Non - Leap Year");
        }
    }
}

输入：

2012

输出：

2012 : Leap Year