java——第三天

package day01;

public class VarDemo {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println("hello world!");
        int a;
        a=12;
        char myChar='A';
        System.out.println(myChar);
        
        byte myByte=127;
        System.out.println(myByte);

    }

}

---

package day01;
import java.util.Scanner;

public class ScoreLevel {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner scan=new Scanner(System.in);
        int score=scan.nextInt();
        if(score>=90) {
            System.out.println("A");
        }
        else if(score>=80) {
            System.out.println("B");
        }
        else {
            System.out.println("c");
        }
    }

}

---

package day01;
import java.util.Scanner;
public class Homework {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
//        int a=5;
//        if(a>3) {
//            int b=8;
//            System.out.println(a);
//            System.out.println(b);
//        }
//        System.out.println(a);
//        System.out.println(b);
        Scanner sacn=new Scanner(System.in);
        System.out.println("please input your salary:");
        double salary=sacn.nextDouble();//输入您的工资
        double taxSalary=salary-5000;//计税工资
        double tax=0.0;//税率、
        if(taxSalary<=0) {
            tax=0.0;
        }else if (taxSalary<=3000) {
            tax=0.03;
        }
        
        
        System.out.println(salary+"-------------"+tax);
        
        

    }

}

---

package day01;
import java.util.Scanner;
public class 猜测一个随机数 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner scanner=new Scanner(System.in);
        int myRandom=(int)(Math.random()*10+1);
        System.out.println(myRandom);

    }

}

---

package day01;
import java.util.Scanner;

import javax.imageio.ImageTranscoder;
public class 猜测一个随机数 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
//        Scanner scanner=new Scanner(System.in);
//        int myRandom=(int)(Math.random()*10+1);
//        System.out.println(myRandom);
        
        
//        long sum=0;
//        for (int i=1;i<=10;i++) {
//            sum=sum*10+9;
//            System.out.println(sum);
//        }
        
        
        for (int i=1;i<=5;i++) {
            System.out.println(1.0/i);
        }
        
    }

}

 

---

package day01;

public class arraydemo {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int[] arr=new int[100];
        for (int i=0;i<arr.length;i++) {
            arr[i]=i*2+5;
            //continue;
        }
        for(int j =0;j<arr.length;j++) {
            System.out.print(arr[j]);
        }
        System.out.println();
        for(int j =arr.length-1;j>=0;j--) {
            System.out.print(arr[j]);
        }
    }

}

---

package week1;
import java.util.Arrays;
public class MaxOfArray {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int[] arr=new int[4];
//        for(int i :arr) {
//            System.out.println(i);
//        }
        System.out.println(arr.length);
        arr=Arrays.copyOf(arr, arr.length+1);
        System.out.println(arr.length);
        
        
        long a=System.currentTimeMillis();
        Arrays.sort(arr);
        long b=System.currentTimeMillis();
        System.out.println(b-a);

    }

}