java——第三天

 1 package day01;
 2 
 3 public class VarDemo {
 4 
 5     public static void main(String[] args) {
 6         // TODO Auto-generated method stub
 7         System.out.println("hello world!");
 8         int a;
 9         a=12;
10         char myChar='A';
11         System.out.println(myChar);
12         
13         byte myByte=127;
14         System.out.println(myByte);
15 
16     }
17 
18 }

 1 package day01;
 2 import java.util.Scanner;
 3 
 4 public class ScoreLevel {
 5 
 6     public static void main(String[] args) {
 7         // TODO Auto-generated method stub
 8         Scanner scan=new Scanner(System.in);
 9         int score=scan.nextInt();
10         if(score>=90) {
11             System.out.println("A");
12         }
13         else if(score>=80) {
14             System.out.println("B");
15         }
16         else {
17             System.out.println("c");
18         }
19     }
20 
21 }

 1 package day01;
 2 import java.util.Scanner;
 3 public class Homework {
 4 
 5     public static void main(String[] args) {
 6         // TODO Auto-generated method stub
 7 //        int a=5;
 8 //        if(a>3) {
 9 //            int b=8;
10 //            System.out.println(a);
11 //            System.out.println(b);
12 //        }
13 //        System.out.println(a);
14 //        System.out.println(b);
15         Scanner sacn=new Scanner(System.in);
16         System.out.println("please input your salary:");
17         double salary=sacn.nextDouble();//输入您的工资
18         double taxSalary=salary-5000;//计税工资
19         double tax=0.0;//税率、
20         if(taxSalary<=0) {
21             tax=0.0;
22         }else if (taxSalary<=3000) {
23             tax=0.03;
24         }
25         
26         
27         System.out.println(salary+"-------------"+tax);
28         
29         
30 
31     }
32 
33 }

View Code

 1 package day01;
 2 import java.util.Scanner;
 3 public class 猜测一个随机数 {
 4 
 5     public static void main(String[] args) {
 6         // TODO Auto-generated method stub
 7         Scanner scanner=new Scanner(System.in);
 8         int myRandom=(int)(Math.random()*10+1);
 9         System.out.println(myRandom);
10 
11     }
12 
13 }

 1 package day01;
 2 import java.util.Scanner;
 3 
 4 import javax.imageio.ImageTranscoder;
 5 public class 猜测一个随机数 {
 6 
 7     public static void main(String[] args) {
 8         // TODO Auto-generated method stub
 9 //        Scanner scanner=new Scanner(System.in);
10 //        int myRandom=(int)(Math.random()*10+1);
11 //        System.out.println(myRandom);
12         
13         
14 //        long sum=0;
15 //        for (int i=1;i<=10;i++) {
16 //            sum=sum*10+9;
17 //            System.out.println(sum);
18 //        }
19         
20         
21         for (int i=1;i<=5;i++) {
22             System.out.println(1.0/i);
23         }
24         
25     }
26 
27 }

 1 package day01;
 2 
 3 public class arraydemo {
 4 
 5     public static void main(String[] args) {
 6         // TODO Auto-generated method stub
 7         int[] arr=new int[100];
 8         for (int i=0;i<arr.length;i++) {
 9             arr[i]=i*2+5;
10             //continue;
11         }
12         for(int j =0;j<arr.length;j++) {
13             System.out.print(arr[j]);
14         }
15         System.out.println();
16         for(int j =arr.length-1;j>=0;j--) {
17             System.out.print(arr[j]);
18         }
19     }
20 
21 }

 1 package week1;
 2 import java.util.Arrays;
 3 public class MaxOfArray {
 4 
 5     public static void main(String[] args) {
 6         // TODO Auto-generated method stub
 7         int[] arr=new int[4];
 8 //        for(int i :arr) {
 9 //            System.out.println(i);
10 //        }
11         System.out.println(arr.length);
12         arr=Arrays.copyOf(arr, arr.length+1);
13         System.out.println(arr.length);
14         
15         
16         long a=System.currentTimeMillis();
17         Arrays.sort(arr);
18         long b=System.currentTimeMillis();
19         System.out.println(b-a);
20 
21     }
22 
23 }