第二次上机作业

1、编写程序， 输入变量x的值，如果是1，输出x=1，如果是5，输出x=5，如果是 10，输出 x=10，除了以上几个值，都输出x=none。（知识点：if条件语句）
import java.util.*;

public class shuchuXzhi {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入一个数");
        double x = input.nextDouble();
        if (x == 1) {
            System.out.println("x=1");
        } else if (x == 5) {
            System.out.println("x=5");
        } else if (x == 10) {
            System.out.println("x==10");
        } else {
            System.out.println("x=none");
        }
    }

}
2、用switch结构实现第1题
import java.util.*;

public class huanzhongfangshi {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("请输入一个数");
        int a=input.nextInt();
        switch(a){
        case 1:
            a=1;
            System.out.println("a=1");
            break;
        case 5:
            a=5;
            System.out.println("a=5");
            break;
        case 10:
            a=10;
            System.out.println("a=10");
            break;
            default:
                System.out.println("none");
                break;
        }
        
    }
}
3、判断一个数字是否能被5和6同时整除（打印能被5和6整除），或只能被5整除（打印能被5整 除），或只能被6整除，（打印能被6整除），不能被5或6整除，（打印不能被5或6整除）
import java.util.*;

public class panduan {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入一个数");
        int a = input.nextInt();
        if (a % 5 == 0 && a % 6 == 0) {
            System.out.println("能被5和6整除");
        } else if (a % 5 == 0) {
            System.out.println("能被5整除");
        } else if (a % 6 == 0) {
            System.out.println("能被6整除");
        } else {
            System.out.println("不能被5和6整除");
        }
    }
}
4、输入一个0～100的分数，如果不是0～100之间，打印分数无效，根据分数等级打印 A(90-100),B(80-89),C,D,E（知识点：条件语句if elseif）
import java.util.*;

public class fenshu {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入一个数");
        int a = input.nextInt();
        if (a < 0 || a > 100) {
            System.out.println("分数无效");
        } else if (a < 100 && a >= 90) {
            System.out.println("A");
        } else if (a < 90 && a >= 80) {
            System.out.println("B");
        } else if (a < 80 && a >= 70) {
            System.out.println("C");
        } else if (a < 70 && a >= 60) {
            System.out.println("D");
        }

    }

}
5、输入三个整数x,y,z，请把这三个数由小到大输出（知识点：条件语句）
import java.util.*;

public class paixu {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("请输入任意三个整数");
        int a = input.nextInt();
        int b = input.nextInt();
        int c = input.nextInt();
        if (a > b) {
            if (b > c) {
                System.out.println("按从大到小排序为：" + c + "," + b + "," + a);
            } else if (c > a) {
                System.out.println("按从大到小排序为：" + a + "," + a + "," + c);
            } else {
                System.out.println("按从大到小排序为：" + b + "," + c + "," + a);
            }
        } else {
            if (c < a) {
                System.out.println("按从大到小排序为：" + c + "," + a + "," + b);
            } else if (c > b) {
                System.out.println("按从大到小排序为：" + a + "," + b + "," + c);
            } else {
                System.out.println("按从大到小排序为：" + a + "," + c + "," + b);
            }
        }
    }
}