第二次上机练习

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）

package huaerzi;
import java.util.Scanner;
public class huada {
    public static void main(String[] args) {
          // TODO Auto-generated method stub
         Scanner in =new Scanner(System.in);
         System.out.println("请输入数字:");{
            int a = in.nextInt();
            if(a==1 || a==5 || a==10) {
                System.out.println("x="+a);
            }else {
             System.out.println("x=none");}
    }
}
}

2.用switch结构实现第1题

package huaerzi;
import java.util.Scanner;
public class huada {
    public static void main(String[] args) {
          // TODO Auto-generated method stub
        Scanner huaer= new Scanner(System.in);
        System.out.println("请输入a的值");
        int a=huaer.nextInt();
        switch(a) {
        case 1: 
        case 5: 
        case 10:
            System.out.println("a="+a);break;
        default:
            System.out.println("a=none");
             System.out.println("a=none");}
    }
}

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）

package huaerzi;
import java.util.Scanner;
public class huada {
    public static void main(String[] args) {
          // TODO Auto-generated method stub
        System.out.println("请输入一个整数");
        Scanner scanner = new Scanner(System.in);
        int a = scanner.nextInt();
        if (a % 5 == 0 && a % 6 == 0) {
        System.out.println("您输入的数字" +a + "能被5和6整除");
        } else if (a % 5 == 0) {
        System.out.println("您输入的数字" + a + "能被5整除");
        } else if (a % 6 == 0) {
        System.out.println("您输入的数字" + a + "能被6整除");
        } else {
        System.out.println("您输入的数字不能被5或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）

package huaerzi;
import java.util.Scanner;
public class huada {
    public static void main(String[] args) {
          // TODO Auto-generated method stub
        System.out.println("请输入一个整数");
        Scanner scanner = new Scanner(System.in);
        int grade = scanner.nextInt();
         if ((grade>100)||(grade<0)) {
        System.out.println("无效");
        } else if ((grade>=80)&&(grade<90)) {
        System.out.println("B");
        } else if ((grade>=90)&&(grade<=100)) {
        System.out.println("A");
        } else  if ((grade>=70)&&(grade<80)){
        System.out.println("C");
        } else if ((grade>=60)&&(grade<70)){
        System.out.println("D");
        }else System.out.println("E");
    }
}

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）

package huaerzi;
import java.util.Scanner;
public class huada {
    public static void main(String[] args) {
          // TODO Auto-generated method stub
        Scanner sc  = new Scanner(System.in);
        System.out.println("输入三个数");
                int x = sc.nextInt();
                int y = sc.nextInt();
                int z = sc.nextInt();
                if(x>y){
                    if(y>z){
                        System.out.println(x+","+y+","+z);
                    }else if(x<z){
                        System.out.println(z+","+x+","+y);
                    }else{
                        System.out.println(x+","+z+","+y);
    
                    }
                }else if(y>x){
                    if(x>z){
                        System.out.println(y+","+x+","+z);
                    }else if(y<z){
                        System.out.println(z+","+y+","+x);
                    }else{
                        System.out.println(y+","+z+","+x);

                    }
                }
    }

}