9.22（代码测试）

CalculateN.java

 1 import java.math.BigInteger;
 2 import java.util.Scanner;
 3 
 4 
 5 public class CalculateN {
 6 
 7     /**
 8      * @param args
 9      */
10     public static void main(String[] args) {
11         System.out.print("������N��");
12         Scanner scanner=new Scanner(System.in);
13         int number=scanner.nextInt();
14         System.out.println(number+"!="+calculateN2(number));
15         
16     }
17     
18     public static long calculateN(int n) {
19         if(n==1 || n==0){
20             return 1;
21         }
22         
23         return n*calculateN(n-1);
24     }
25 
26     public static BigInteger calculateN2(int n) {
27         if(n==1 || n==0){
28             return BigInteger.valueOf(1);
29         }
30         return BigInteger.valueOf(n).multiply(calculateN2((n-1)));
31     }
32 }

运行结果

CompareFloatNumber.java

 1 public class CompareFloatNumber {
 2 
 3     /**
 4      * @param args
 5      */
 6     public static void main(String[] args) {
 7         //compare();
 8         compare2();
 9 
10     }
11 
12     private static void compare() {
13         double i = 0.0001;
14         double j = 0.00010000000000000001;
15         System.out.println(i==j);  //�����true
16     }
17     private static void compare2() {
18         double i = 0.0001;
19         double j = 0.00010000000000000001;
20         if(Math.abs(i-j)<1e-10){
21             System.out.println("true");  
22         }
23         else
24         {
25             System.out.println("false");
26         }
27         
28     }
29 
30 }

运行结果

MethodOverload.java

 1 package ceshi;// MethodOverload.java
 2 // Using overloaded methods
 3 
 4 public class MethodOverload {
 5 
 6     public static void main(String[] args) {
 7         System.out.println("The square of integer 7 is " + square(7));
 8         System.out.println("\nThe square of double 7.5 is " + square(7.5));
 9     }
10 
11     public static int square(int x) {
12         return x * x;
13     }
14 
15     public static double square(double y) {
16         return y * y;
17     }
18 }

运行结果

RandomInt.java

 1 package ceshi;// RandomInt.java
 2 // Shifted, scaled random integers
 3 import javax.swing.JOptionPane;
 4 
 5 public class RandomInt {
 6     public static void main( String args[] )
 7     {
 8         int value;
 9         String output = "";
10 
11         for ( int i = 1; i <= 20; i++ ) {
12             value = 1 + (int) ( Math.random() * 6 );
13             output += value + "  ";
14 
15             if ( i % 5 == 0 )
16                 output += "\n";
17         }
18 
19         JOptionPane.showMessageDialog( null, output,
20                 "20 Random Numbers from 1 to 6",
21                 JOptionPane.INFORMATION_MESSAGE );
22 
23         System.exit( 0 );
24     }
25 }

运行结果

RollDie.java

 1 package ceshi;// RollDie.java
 2 // Roll a six-sided die 6000 times
 3 import javax.swing.*;
 4 
 5 public class RollDie {
 6     public static void main( String args[] )
 7     {
 8         int frequency1 = 0, frequency2 = 0,
 9                 frequency3 = 0, frequency4 = 0,
10                 frequency5 = 0, frequency6 = 0, face;
11 
12         // summarize results
13         for ( int roll = 1; roll <= 6000; roll++ ) {
14             face = 1 + (int) ( Math.random() * 6 );
15 
16             switch ( face ) {
17                 case 1:
18                     ++frequency1;
19                     break;
20                 case 2:
21                     ++frequency2;
22                     break;
23                 case 3:
24                     ++frequency3;
25                     break;
26                 case 4:
27                     ++frequency4;
28                     break;
29                 case 5:
30                     ++frequency5;
31                     break;
32                 case 6:
33                     ++frequency6;
34                     break;
35             }
36         }
37 
38         JTextArea outputArea = new JTextArea( 7, 10 );
39 
40         outputArea.setText(
41                 "Face\tFrequency" +
42                         "\n1\t" + frequency1 +
43                         "\n2\t" + frequency2 +
44                         "\n3\t" + frequency3 +
45                         "\n4\t" + frequency4 +
46                         "\n5\t" + frequency5 +
47                         "\n6\t" + frequency6 );
48 
49         JOptionPane.showMessageDialog( null, outputArea,
50                 "Rolling a Die 6000 Times",
51                 JOptionPane.INFORMATION_MESSAGE );
52         System.exit( 0 );
53     }
54 }

运行结果

SquareInt.java

 1 package ceshi;
 2 
 3 public class SquareInt {
 4 
 5     public static void main(String[] args) {
 6         int result;
 7 
 8         for (int x = 1; x <= 10; x++) {
 9             result = square(x);
10             // Math����Ҳ�ṩ����ƽ�����ķ���
11             // result=(int)Math.pow(x,2);
12             System.out.println("The square of " + x + " is " + result + "\n");
13         }
14     }
15 
16     // �Զ�����ƽ�����ľ�̬����
17     public static int square(int y) {
18         return y * y;
19     }
20 }

运行结果

TestMath.java

 1 package ceshi;
 2 
 3 
 4 public class TestMath
 5 {
 6     public static void main(String[] args)
 7     {
 8         /*---------��������������---------*/
 9         //������ת���Ƕ�
10         System.out.println("Math.toDegrees(1.57)��" + Math.toDegrees(1.57));
11         //���Ƕ�ת��Ϊ����
12         System.out.println("Math.toRadians(90)��" + Math.toRadians(90));
13         //���㷴���ң����صĽǶȷ�Χ�� 0.0 �� pi ֮�䡣
14         System.out.println("Math.acos(0.3)��" + Math.acos(1.2));
15         //���㷴���ң����صĽǶȷ�Χ�� -pi/2 �� pi/2 ֮�䡣
16         System.out.println("Math.asin(0.8)��" + Math.asin(0.8));
17         //���㷴���У����صĽǶȷ�Χ�� -pi/2 �� pi/2 ֮�䡣
18         System.out.println("Math.atan(2.3)��" + Math.atan(2.3));
19         //�����������ҡ�
20         System.out.println("Math.cos(1.57)��" + Math.cos(1.57));
21         //����ֵ��˫�����ҡ�
22         System.out.println("Math.cosh(1.2 )��" + Math.cosh(1.2 ));
23         //��������
24         System.out.println("Math.sin(1.57 )��" + Math.sin(1.57 ));
25         //����˫������
26         System.out.println("Math.sinh(1.2 )��" + Math.sinh(1.2 ));
27         //������������
28         System.out.println("Math.tan(0.8 )��" + Math.tan(0.8 ));
29         //����˫������
30         System.out.println("Math.tanh(2.1 )��" + Math.tanh(2.1 ));
31         //���������� (x, y) ת���ɼ����� (r, thet));���������ý� theta��
32         System.out.println("Math.atan2(0.1, 0.2)��" + Math.atan2(0.1, 0.2));
33         /*---------������ȡ������---------*/
34         //ȡ��������С��Ŀ���������������
35         System.out.println("Math.floor(-1.2 )��" + Math.floor(-1.2 ));
36         //ȡ�������ش���Ŀ��������С������
37         System.out.println("Math.ceil(1.2)��" + Math.ceil(1.2));
38         //��������ȡ��
39         System.out.println("Math.round(2.3 )��" + Math.round(2.3 ));
40         /*---------�����dz˷���������ָ������---------*/
41         //����ƽ������
42         System.out.println("Math.sqrt(2.3 )��" + Math.sqrt(2.3 ));
43         //������������
44         System.out.println("Math.cbrt(9)��" + Math.cbrt(9));
45         //����ŷ���� e ��n���ݡ�
46         System.out.println("Math.exp(2)��" + Math.exp(2));
47         //���� sqrt(x2��" +y2)��û���м���������硣
48         System.out.println("Math.hypot(4 , 4)��" + Math.hypot(4 , 4));
49         // ���� IEEE 754 ��׼�Ĺ涨�����������������������㡣
50         System.out.println("Math.IEEEremainder(5 , 2)��" + Math.IEEEremainder(5 , 2));
51         //����˷�
52         System.out.println("Math.pow(3, 2)��" + Math.pow(3, 2));
53         //������Ȼ����
54         System.out.println("Math.log(12)��" + Math.log(12));
55         //�������Ϊ 10 �Ķ�����
56         System.out.println("Math.log10(9)��" + Math.log10(9));
57         // �ز����� 1 ֮�͵���Ȼ������
58         System.out.println("Math.log1p(9)��" + Math.log1p(9));
59         /*---------�����Ƿ�����ص�����---------*/
60         //�������ֵ��
61         System.out.println("Math.abs(-4.5)��" + Math.abs(-4.5));
62         //���Ÿ�ֵ�����ش��еڶ������������ŵĵ�һ�����������
63         System.out.println("Math.copySign(1.2, -1.0)��" + Math.copySign(1.2, -1.0));
64         //���ź������������Ϊ 0���򷵻� 0������������� 0���򷵻� 1.0���������С�� 0���򷵻� -1.0��
65         System.out.println("Math.signum(2.3)��" + Math.signum(2.3));
66         /*---------�����Ǵ�С��ص���������---------*/
67         //�ҳ����ֵ
68         System.out.println("Math.max(2.3 , 4.5)��" + Math.max(2.3 , 4.5));
69         //������Сֵ
70         System.out.println("Math.min(1.2 , 3.4)��" + Math.min(1.2 , 3.4));
71         //���ص�һ�������͵ڶ�������֮�����һ���������ڵĸ�������
72         System.out.println("Math.nextAfter(1.2, 1.0)��" + Math.nextAfter(1.2, 1.0));
73         //���ر�Ŀ�����Դ�ĸ�����
74         System.out.println("Math.nextUp(1.2 )��" + Math.nextUp(1.2 ));
75         //����һ��α���������ֵ���ڵ��� 0.0 ��С�� 1.0��
76         System.out.println("Math.random()��" + Math.random());
77     }
78 }

运行结果

TestRandom.java

 1 package ceshi;
 2 
 3 import java.util.*;
 4 
 5 public class TestRandom
 6 {
 7     public static void main(String[] args)
 8     {
 9         Random rand = new Random();
10         System.out.println("rand.nextBoolean()��" + rand.nextBoolean());
11         byte[] buffer = new byte[16];
12         rand.nextBytes(buffer);
13         System.out.println(Arrays.toString(buffer));
14         //����0.0~1.0֮���α���double��
15         System.out.println("rand.nextDouble()��" + rand.nextDouble());
16         //����0.0~1.0֮���α���float��
17         System.out.println("rand.nextFloat()��" + rand.nextFloat());
18         //����ƽ��ֵ�� 0.0����׼���� 1.0��α��˹��
19         System.out.println("rand.nextGaussian()��" + rand.nextGaussian());
20         //����һ������long����ȡֵ��Χ��α�������
21         System.out.println("rand.nextInt()��" + rand.nextInt());
22         //����0~26֮���α�������
23         System.out.println("rand.nextInt(26)��" + rand.nextInt(26));
24         //����һ������long����ȡֵ��Χ��α�������
25         System.out.println("rand.nextLong()��" +  rand.nextLong());
26     }
27 }

运行结果

TestSeed.java

 1 package ceshi;
 2 
 3 import java.util.Random;
 4 
 5 public class TestSeed
 6 {
 7     public static void main(String[] args)
 8     {
 9         Random r1 = new Random(50);
10         System.out.println("��һ������Ϊ50��Random����");
11         System.out.println("r1.nextBoolean():\t" + r1.nextBoolean());
12         System.out.println("r1.nextInt():\t\t" + r1.nextInt());
13         System.out.println("r1.nextDouble():\t" + r1.nextDouble());
14         System.out.println("r1.nextGaussian():\t" + r1.nextGaussian());
15         System.out.println("---------------------------");
16 
17         Random r2 = new Random(50);
18         System.out.println("�ڶ�������Ϊ50��Random����");
19         System.out.println("r2.nextBoolean():\t" + r2.nextBoolean());
20         System.out.println("r2.nextInt():\t\t" + r2.nextInt());
21         System.out.println("r2.nextDouble():\t" + r2.nextDouble());
22         System.out.println("r2.nextGaussian():\t" + r2.nextGaussian());
23         System.out.println("---------------------------");
24 
25         Random r3 = new Random(100);
26         System.out.println("����Ϊ100��Random����");
27         System.out.println("r3.nextBoolean():\t" + r3.nextBoolean());
28         System.out.println("r3.nextInt():\t\t" + r3.nextInt());
29         System.out.println("r3.nextDouble():\t" + r3.nextDouble());
30         System.out.println("r3.nextGaussian():\t" + r3.nextGaussian());
31 
32 
33         Random r4 = new Random(System.currentTimeMillis());
34         System.out.println("�Ե�ǰʱ��Ϊ���ӵ�Random����");
35         System.out.println("r3.nextBoolean():\t" + r4.nextBoolean());
36         System.out.println("r3.nextInt():\t\t" + r4.nextInt());
37         System.out.println("r3.nextDouble():\t" + r4.nextDouble());
38         System.out.println("r3.nextGaussian():\t" + r4.nextGaussian());
39     }
40 }

运行结果

VariableArgumentsTest.java

 1 package ceshi;
 2 
 3 import java.awt.*;
 4 import java.awt.event.*;
 5 import java.util.*;
 6 
 7 
 8 public class VariableArgumentsTest{
 9 
10     public static double max(double...values)
11     {
12         double largest=Double.MIN_VALUE;
13         for (double v:values)
14             if(v>largest) largest=v;
15         return largest;
16     }
17 
18     public static void main(String args[]) {
19 
20         System.out.println("Max:"+max(1,11,300,2,3));
21 
22     }
23 }

运行结果

 

posted @ 2023-09-22 17:42  Code13  阅读(4)  评论(0)  编辑  收藏  举报