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.Scanner;
public class se {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println("请输入x的值");
          Scanner input=new Scanner(System.in);   
          int x = input.nextInt();
          if(x==1) {
           System.out.println("x="+x);
          }else if(x==5) {
           System.out.println("x="+x);
          }else if(x==10) {
           System.out.println("x="+x);
          }else {
           System.out.println("x=none");
          }
         }

        }

 

 2.用switch结构实现第1题

package jxk;
import java.util.Scanner;
public class se {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println("请输入x的值");
          Scanner input=new Scanner(System.in);   
          int x = input.nextInt();
          switch(x/1) {
          case 1: System.out.println("x="+x);break;
          case 5: System.out.println("x="+x);break;
          case 10: System.out.println("x="+x);break;
          default: System.out.println("x=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.Scanner;
public class se {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println("请输入一个数字");
          Scanner input=new Scanner(System.in);   
          int x = input.nextInt();
          if(x%5==0&&x%6==0) {
           System.out.println("可以同时被5和6整除");
          }else if(x%5==0) {
           System.out.println("可以被5整除");
          }else if(x%6==0) {
           System.out.println("可以被6整除");
          }else {
           System.out.println("不可以被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)

System.out.println("请输入一个0到100的分数");
  Scanner input=new Scanner(System.in);   
  double x = input.nextInt();
  if(x>100||x<0) {
   System.out.println("分数无效");
  }else if(x>=90&&x<=100) {
   System.out.println("A");
  }else if(x>=80&&x<=89) {
   System.out.println("B");
  }else if(x>=80&&x<=79) {
   System.out.println("C");
  }else if(x>=70&&x<=69) {
   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)

System.out.println("请输入三个整数,我由大到小排列");
  Scanner input=new Scanner(System.in);   
  int a=input.nextInt();
  int b=input.nextInt();
  int c=input.nextInt();
  int max,middle,min;
  max = a;
  if(b > a && b > c ){
  max = b;
  } 
  if(c > a && c > b){
  max = c;
  }
  min = a;
  if(b < a && b < c){
  min = b;
  }
  if(c < a && c < b){
  min = c;
  }
  middle = (a + b + c) - (max + min);
  System.out.println(min + ","+ middle + "," + max);
 }

}