判断平年闰年

package test1;

import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int year = sc.nextInt();

        if(year%100!=0&&year%4==0||year%400==0) {
            System.out.printf("%d是闰年", year);
        }else System.out.printf("%d不是闰年",year);
    }
}

switch语句判断星期

package test1;

import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int day = sc.nextInt();
        String name;

        switch(day){
            case 1:
                name = "Monday";
                break;
            case 2:
                name = "Tuesday";
                break;
            case 3:
                name = "Wednesday";
                break;
            case 4:
                name = "Thursday";
                break;
            case 5:
                name = "Friday";
                break;
            case 6:
                name = "Saturday";
                break;
            case 7:
                name = "Sunday";
                break;
            default:
                name = "invalid";
        }

//        System.out.println(name);
        //可以用%s格式化输出String
        System.out.printf("%s",name);
    }
}

遍历

package test1;

import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        int [] a = {1,2,3,4,5};
        for(int x : a) System.out.println(x);
    }
}

编辑器优化fori