Day3.选择结构的练习

package Test3;

import java.util.Scanner;

/**
 * @author:Xem626
 * @date 2022/7/3   8:50
 * @TODO
 */
public class Test2 {
    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        System.out.println("请输入一个数：");
        int a=scanner.nextInt();

        System.out.println("输入的数为："+a);
        if(a%2==0){
            System.out.println("该数为偶数");
        }else{
            System.out.println("该数为奇数");
        }
    }
}

例3：
键盘录入月份的值，输出相应的季节
春 3，4，5
夏 6，7，8
秋 9，10，11
冬 12，1，2

方法1.

package Test3;

import java.util.Scanner;

/**
 * @author:Xem626
 * @date 2022/7/3   9:02
 * @TODO
 */
public class Test3 {
    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        System.out.println("请输入月份：");
        int a =scanner.nextInt();

        switch(a){
            case 3:
            case 4:
            case 5:
                System.out.println("春");
                break;
            case 6:
            case 7:
            case 8:
                System.out.println("夏");
                break;
            case 9:
            case 10:
            case 11:
                System.out.println("秋");
                break;
            case 12:
            case 1:
            case 2:
                System.out.println("冬");
                break;
            default:
                System.out.println("输入错误");
                break;
        }

    }
}

方法2.

package Test3;

import java.util.Scanner;

/**
 * @author:Xem626
 * @date 2022/7/3   9:29
 * @TODO
 */
public class Test4 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入月份：");
        int mouth = scanner.nextInt();
        if (mouth < 1 || mouth > 12) {
            System.out.println("输入月份错误！");
        }else if (mouth >= 3 && mouth <= 5) {
            System.out.println("春");
        }else if(mouth >=6 && mouth<=8){
            System.out.println("夏");
        }else if(mouth >=9 && mouth <=11){
            System.out.println("秋");
        }else {
            System.out.println("冬");
        }
    }
}

例3：
获取三个数中最大数
1.

package Test3;

import java.util.Scanner;

/**
 * @author:Xem626
 * @date 2022/7/3   9:38
 * @TODO
 */
public class Test5 {
    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        System.out.println("请输入第一个数");
        int a=scanner.nextInt();
        System.out.println("请输入第二个数");
        int b=scanner.nextInt();
        System.out.println("请输入第三个数");
        int c=scanner.nextInt();
        int max=0;
        if(a>b){
            max=a;
        }else {
            max=b;
        }
        if(max>c){
            System.out.println("最大数为："+max);
        }else{
            max=c;
            System.out.println("最大数为："+c);
        }

    }
}

2.

package Test3;

import java.util.Scanner;

/**
 * @author:Xem626
 * @date 2022/7/3   9:38
 * @TODO
 */
public class Test5 {
    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        System.out.println("请输入第一个数");
        int a=scanner.nextInt();
        System.out.println("请输入第二个数");
        int b=scanner.nextInt();
        System.out.println("请输入第三个数");
        int c=scanner.nextInt();
        int max=0;
        if(a>b){
            if(a>c){
                max=a;
            }else{
                max=c;
            }
        }else {
            if(b>c){
                max=b;
            }else{
                max=c;
            }
        }
        System.out.println("最大值为："+max);
    }
}

例4：
判断输出字符串（Switch语句）

package Test3;

import java.util.Scanner;

/**
 * @author:Xem626
 * @date 2022/7/3   10:46
 * @TODO
 */
public class Test7 {
    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        System.out.println("请输入你要判断的字符串");
        String string=scanner.next();
        System.out.println("你输入的字符串为："+string);
        switch (string){
            case "hello":
                System.out.println("字符串为hello");
                break;
            case "world":
                System.out.println("字符串为world");
                break;
            default:
                System.out.println("无法判断");
                break;
        }
    }
}