Upload original JAVA语言程序设计 course files (part 26)

Java程序学习和训练/0023无参构造方法/Main.java

@@ -1,3 +1,28 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:6cef0f50c0b943c546d91d798b1354d2ed688a6c4e8f50fdb035732462ebcbb2
-size 447
+
+
+// 类A
+class A {
+    A() {
+        System.out.println("Constructor of class A");
+    }
+}
+
+// 类B
+class B {
+    B() {
+        System.out.println("Constructor of class B");
+    }
+}
+
+// 类C，继承自A，并包含一个B的成员
+class C extends A {
+    B b = new B();
+}
+
+// 测试类
+public class Main {
+    public static void main(String[] args) {
+        // 创建类C的实例对象
+        C c = new C();
+    }
+}

Java程序学习和训练/0024构造超类/Main.java

@@ -1,3 +1,36 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:ee551aea5d1325ea501736f38138c40f76622532c5d00c84e5664c7b5d86c54f
-size 840
+// 超类A
+class A {
+    private int value;
+
+    // 非默认构造方法
+    public A(int value) {
+        this.value = value;
+        System.out.println("Constructor of class A with value: " + value);
+    }
+}
+
+// 子类B
+class B extends A {
+    // 默认构造方法
+    public B() {
+        // 调用超类A的非默认构造方法
+        super(0);
+        System.out.println("Constructor of class B (default)");
+    }
+
+    // 非默认方法
+    public B(int value) {
+        // 调用超类A的非默认构造方法
+        super(value);
+        System.out.println("Constructor of class B with value: " + value);
+    }
+}
+
+// 测试类
+public class Main {
+    public static void main(String[] args) {
+        // 创建子类B的实例对象
+        B b1 = new B();
+        B b2 = new B(10);
+    }
+}

Java程序学习和训练/0024构造超类/Main.java.bak

@@ -1,3 +1,43 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:b74e720b0259ff49df072349957f15591f7ef6e16455dff4a8b43a707e59d43a
-size 944
+// 超类A
+class A {
+    private int value;
+
+    // 非默认构造方法
+    public A(int value) {
+        this.value = value;
+        System.out.println("Constructor of class A with value: " + value);
+    }
+}
+
+// 子类B
+class B extends A {
+    // 默认构造方法
+    public B() {
+        // 调用超类A的非默认构造方法
+        super(0);
+        System.out.println("Constructor of class B (default)");
+    }
+
+    // 非默认方法
+    public B(int value) {
+        // 调用超类A的非默认构造方法
+        super(value);
+        System.out.println("Constructor of class B with value: " + value);
+    }
+}
+
+// 测试类
+public class Main {
+    public static void main(String[] args) {
+        // 创建子类B的实例对象
+        B b1 = new B();
+        B b2 = new B(10);
+    }
+}
+class  
+{
+	public static void main(String[] args) 
+	{
+		System.out.println("Hello World!");
+	}
+}

Java程序学习和训练/0025重载与派生类/Main.java

@@ -1,3 +1,42 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:23f4a877d6b0f79c28a879189a399f4a7a19f7950c47d5a062443f8b9d9d959f
-size 1323
+// 声明一个类
+class MyClass {
+    // 方法重载，重载了三次
+    void overloadedMethod() {
+        System.out.println("No arguments");
+    }
+
+    void overloadedMethod(int num) {
+        System.out.println("One argument: " + num);
+    }
+
+    void overloadedMethod(int num1, int num2) {
+        System.out.println("Two arguments: " + num1 + ", " + num2);
+    }
+}
+
+// 派生一个新类并增加一个新的重载方法
+class MyDerivedClass extends MyClass {
+    // 增加一个新的重载方法
+    void overloadedMethod(String str) {
+        System.out.println("One argument: " + str);
+    }
+}
+
+// 测试类
+public class Main {
+    public static void main(String[] args) {
+        // 创建 MyClass 的对象
+        MyClass myClass = new MyClass();
+        
+        // 调用不同重载方法
+        myClass.overloadedMethod();            // 调用无参方法
+        myClass.overloadedMethod(10);          // 调用一个参数的方法
+        myClass.overloadedMethod(20, 30);      // 调用两个参数的方法
+        
+        // 创建 MyDerivedClass 的对象
+        MyDerivedClass myDerivedClass = new MyDerivedClass();
+        
+        // 调用新的重载方法
+        myDerivedClass.overloadedMethod("Hello"); // 调用一个参数的方法
+    }
+}

Java程序学习和训练/0026学生类/Test.java.bak

@@ -1,3 +1,7 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:7aa19ca422c2fcbd62dcc475fced839bee2dcf39d9803a0daee747850055e79a
-size 104
+class  
+{
+	public static void main(String[] args) 
+	{
+		System.out.println("Hello World!");
+	}
+}

Java程序学习和训练/0027引入包/Main.java

@@ -1,3 +1,17 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:70119b1e9bd805ff7fdfb95c41404a905d2a189c9df2da64189136da8c408944
-size 526
+import java.util.Scanner;
+import java.util.*;
+
+public class Main {
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+        
+        System.out.print("请输入一个数字：");
+        double number = scanner.nextDouble();
+        
+        double squareRoot = Math.sqrt(number); // 可以直接使用 sqrt() 方法，不需要前缀 Math
+        
+        System.out.println("该数字的平方根是：" + squareRoot);
+        
+        scanner.close();
+    }
+}

Java程序学习和训练/0027引入包/Main.java.bak

@@ -1,3 +1,17 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:15a2de0c8747bead064e777e3c10de6762974049dc5a46add6e72da32f19e80c
-size 521
+import java.util.Scanner;
+import java.util.*;
+
+public class Main {
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+        
+        System.out.print("请输入一个数字：");
+        double number = scanner.nextDouble();
+        
+        double squareRoot = sqrt(number); // 可以直接使用 sqrt() 方法，不需要前缀 Math
+        
+        System.out.println("该数字的平方根是：" + squareRoot);
+        
+        scanner.close();
+    }
+}

Java程序学习和训练/0028忽略倍数/Main.java

@@ -1,3 +1,16 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:2ff35f79d161e0dff2492b3728b21e65062f27aa9451fa98be85f8fbbe4d6db2
-size 229
+public class Main
+{
+	public static void main(String args[])
+		{
+				for (int i=0;i<100 ;i++ )
+				{
+					if (i%3==0||i%5==0)
+					{
+						continue;
+					}
+					else {
+						System.out.println(i);
+					}
+				}
+		}
+}

Java程序学习和训练/0028忽略倍数/Main.java.bak

@@ -1,3 +1,16 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:0ee9146af81f3787a2661c6fc8718381f9ebbeb02de46bb453fd3497417e0480
-size 229
+public class Main
+{
+	public static void main(String args[])
+		{
+				for (int i=0;i<100 ;i++ )
+				{
+					if (i%3==0&&i%5==0)
+					{
+						continue;
+					}
+					else {
+						System.out.println(i);
+					}
+				}
+		}
+}

Java程序学习和训练/0029继承你的护甲/Item.java.bak

@@ -1,3 +1,7 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:7aa19ca422c2fcbd62dcc475fced839bee2dcf39d9803a0daee747850055e79a
-size 104
+class  
+{
+	public static void main(String[] args) 
+	{
+		System.out.println("Hello World!");
+	}
+}

Java程序学习和训练/0029继承你的护甲/Main.java

@@ -1,3 +1,27 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:e7eb9449a031e166c93d4368f58f200b4ad6f80d0a480308866c110b0dde3443
-size 649
+class Armor extends Item {
+    int ac; // ���׵ȼ�
+
+    public Armor(int ac, int price) {
+        this.ac = ac;
+        this.price = price;
+    }
+}
+
+class Item {
+    int price; // �۸�
+
+    public Item(int price) {
+        this.price = price;
+    }
+}
+
+public class Main {
+    public static void main(String[] args) {
+        Armor bujia = new Armor(15, 300); // ����
+        Armor lianjia = new Armor(40, 500); // ����
+
+        System.out.println("����\t�۸�\t���׵ȼ�");
+        System.out.println("����\t" + bujia.price + "\t" + bujia.ac);
+        System.out.println("����\t" + lianjia.price + "\t" + lianjia.ac);
+    }
+}

Java程序学习和训练/0029继承你的护甲/Main.java.bak

@@ -1,3 +1,25 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:3b5bfdfe75ea1104245955c21b3519cfea2a32006de8e8b8891b9bf624a56bb3
-size 464
+ class Armor extends Item
+{
+	int ac;
+}
+
+
+public class Main
+{
+	public static void main(String args[])
+		{
+			Weapen Bujia = new Weapen();
+			Weapen Lianjia = new Weapen();
+			Bujia.ac =15;
+			Bujia.price = 300;
+			Lianjia.ac =40;
+			Lianjia.price = 500;
+		
+			System.out.println("����/t�۸�/t���׵ȼ�");
+			System.out.println("����" + Bujia.price +'/t' + BUjia.ac);
+			System.out.println("����" + Lianjia.price +'/t' + Lianjia.ac);
+	
+
+			
+
+}

Java程序学习和训练/0030接口与实现/Estimator.java

@@ -1,3 +1,78 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:807a4512372135fe82c8cee835de2179734d85b9e62c79b4d6b977d6a0292010
-size 2578
+// ����һ������ƽ��ֵ�Ľӿ�
+interface ComputerAverage {
+    // ����һ�����������ڼ���double���������ƽ��ֵ
+    public double average(double[] x);
+}
+
+// Gymnastics��(�����)ʵ��ComputerAverage�ӿ�
+class Gymnastics implements ComputerAverage {
+    // ʵ�ֽӿ��е�average���������ڼ������ֵ�ƽ��ֵ��ȥ��һ����߷ֺ�һ����ͷ�
+    public double average(double[] x) {
+        int count = x.length;
+        double aver = 0;
+        double temp = 0;
+        
+        // ��������������Ա�ȥ����ߺ���ͷ�
+        for (int i = 0; i < count; i++) {
+            for (int j = i + 1; j < count; j++) {
+                if (x[j] < x[i]) {
+                    temp = x[j];
+                    x[j] = x[i];
+                    x[i] = temp;
+                }
+            }
+        }
+        
+        // ȥ����ߺ���ͷ֣�����ʣ��������ܺ�
+        for (int i = 1; i < count - 1; i++) {
+            aver += x[i];
+        }
+        
+        // ����ƽ����
+        if (count > 2) {
+            aver /= (count - 2);
+        } else {
+            aver = 0;
+        }
+        return aver;
+    }
+}
+
+// School��ʵ��ComputerAverage�ӿ�
+class School implements ComputerAverage {
+    // ʵ�ֽӿ��е�average���������ڼ�������Ԫ�ص�����ƽ��ֵ
+    public double average(double[] x) {
+        int count = x.length;
+        double aver = 0;
+        
+        // �����ܷ�
+        for (int i = 0; i < count; i++) {
+            aver += x[i];
+        }
+        
+        // ����ƽ����
+        aver /= count;
+        return aver;
+    }
+}
+
+// Estimator�����main��������������
+public class Estimator {
+    // main����������ִ�еĿ�ʼ
+    public static void main(String[] args) {
+        double a[] = {9.89, 9.88, 9.99, 9.12, 9.69, 9.76, 8.97}; // ���ѡ�ֵĵ÷�
+        double b[] = {89, 56, 78, 90, 100, 77, 56, 45, 36, 79, 98}; // �༶ѧ���Ŀ��Է���
+        ComputerAverage computer; // ����һ��ComputerAverage�ӿڵı���
+        
+        // ����Gymnastics���ʵ�������������ѡ�ֵ�ƽ���÷�
+        computer = new Gymnastics();
+        double result = computer.average(a); // ����average������������A���ݸ�����x
+        System.out.println(); // �������
+        System.out.printf("���ѡ�����÷֣�%.3f%n", result); // ������ѡ�ֵ�ƽ���÷�
+        
+        // ����School���ʵ����������༶���Ե�ƽ������
+        computer = new School(); // ����School���ʵ��
+        result = computer.average(b); // ����average������������B���ݸ�����x
+        System.out.printf("�༶����ƽ��������%.2f%n", result); // ����༶���Ե�ƽ������
+    }
+}

Java程序学习和训练/0030接口与实现/Estimator.java.bak

@@ -1,3 +1,58 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:c713a2be04701626c26d0a7a4bc88014c882ffda12ef2b3a3e6d19d56f7e4a08
-size 1705
+interface ComputerAverage {
+    public double average(double[] x);
+}
+
+class Gymnastics implements ComputerAverage {
+    public double average(double[] x) {
+        int count = x.length;
+        double aver = 0;
+        double temp = 0;
+        for (int i = 0; i < count; i++) {
+            for (int j = i + 1; j < count; j++) {
+                if (x[j] < x[i]) {
+                    temp = x[j];
+                    x[j] = x[i];
+                    x[i] = temp;
+                }
+            }
+        }
+        for (int i = 1; i < count - 1; i++) {
+            aver += x[i];
+        }
+        if (count > 2) {
+            aver /= (count - 2);
+        } else {
+            aver = 0;
+        }
+        return aver;
+    }
+}
+
+class School implements ComputerAverage {
+    public double average(double[] x) {
+        int count = x.length;
+        double aver = 0;
+        for (int i = 0; i < count; i++) {
+            aver += x[i];
+        }
+        aver /= count;
+        return aver;
+    }
+}
+
+public class Estimator {
+    public static void main(String[] args) {
+        double a[] = {9.89, 9.88, 9.99, 9.12, 9.69, 9.76, 8.97};
+        double b[] = {89, 56, 78, 90, 100, 77, 56, 45, 36, 79, 98};
+        ComputerAverage computer;
+
+        computer = new Gymnastics();
+        double result = computer.average(a); // ����average������������A���ݸ�����x
+        System.out.println();
+        System.out.printf("���ѡ�����÷֣�%.3f%n", result);
+
+        computer = new School(); // ����School���ʵ��
+        result = computer.average(b); // ����average������������B���ݸ�����x
+        System.out.printf("�༶����ƽ��������%.2f%n", result);
+    }
+}

Java程序学习和训练/0031字符串类的截取/Example8_6.java

@@ -1,3 +1,16 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:a709b3c3af1f7833a97d56a9bdb10bc46c5898bbbc3e723b5534edd025b6195a
-size 574
+public class Example8_6 {
+    public static void main(String args[]) {
+        char[] a, c;
+        String s = "1945��8��15���ǿ�սʤ����";
+        
+        // ʹ�� getChars() �����������ַ����д�ŵ�������
+        a = new char[4];
+        s.getChars(11, 15, a, 0);
+        System.out.println(a); // ������� a ������
+        
+        // ʹ�� toCharArray() �����������ַ���ת��Ϊ�ַ�����
+        c = "ʮһ�����ڼ䣬ѧУ���ż���".toCharArray();
+        for (int i = 0; i < c.length; i++)
+            System.out.print(c[i]); // �������ַ����� c ������
+    }
+}

Java程序学习和训练/0031字符串类的截取/Untitled1 - 副本 - 副本 (8).java.bak

@@ -1,3 +1,7 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:7aa19ca422c2fcbd62dcc475fced839bee2dcf39d9803a0daee747850055e79a
-size 104
+class  
+{
+	public static void main(String[] args) 
+	{
+		System.out.println("Hello World!");
+	}
+}

Java程序学习和训练/0032字符串类的转换/Main.java

@@ -1,3 +1,25 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:bb1a1b28ae668023284e8425b04ba4bf12894d7039d7a641d7a232ec79c5d260
-size 960
+import java.util.Arrays;
+import java.io.UnsupportedEncodingException;
+
+public class Main {
+    public static void main(String[] args) {
+        // ʾ��4�����ַ���ת��Ϊ�ֽ����飨ʹ�ò�ͬ���ַ����룩
+        String str = "���";
+        
+        // ʹ��ƽ̨Ĭ���ַ�����
+        byte[] byteArrayDefault = str.getBytes();
+        System.out.println("Ĭ���ַ������ֽ�����: " + Arrays.toString(byteArrayDefault)); // ����ֽ�����
+        
+        try {
+            // ʹ�� UTF-8 ����
+            byte[] byteArrayUTF8 = str.getBytes("UTF-8");
+            System.out.println("UTF-8 �ֽ�����: " + Arrays.toString(byteArrayUTF8)); // ����ֽ�����
+            
+            // ʹ�� GBK ����
+            byte[] byteArrayGBK = str.getBytes("GBK");
+            System.out.println("GBK �ֽ�����: " + Arrays.toString(byteArrayGBK)); // ����ֽ�����
+        } catch (UnsupportedEncodingException e) {
+            e.printStackTrace();
+        }
+    }
+}

Java程序学习和训练/0032字符串类的转换/Main.java.bak

@@ -1,3 +1,15 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:f713776dccb34df04ee3d633e6697303f9ba027a73074904159b531381f54078
-size 532
+import java.util.Arrays;
+import java.io.UnsupportedEncodingException;
+
+public class Main {
+    public static void main(String[] args) {
+        // ʾ��4�����ַ���ת��Ϊ�ֽ����飨ʹ��ָ���ַ����룩
+        String str = "Hello";
+        try {
+            byte[] byteArray = str.getBytes("UTF-8");
+            System.out.println("�ֽ�����: " + Arrays.toString(byteArray)); // ����ֽ����飬�� [72, 101, 108, 108, 111]
+        } catch (UnsupportedEncodingException e) {
+            e.printStackTrace();
+        }
+    }
+}

Java程序学习和训练/0032字符串类的转换/Untitled1 - 副本 - 副本 (10).java.bak

@@ -1,3 +1,10 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:54560c75c332bf5705d185a004853b56007564c660504cb19659b8b5ff0f1bd6
-size 355
+import java.util.Arrays;
+
+public class ByteArrayToStringExample {
+    public static void main(String[] args) {
+        // ʾ��1�����ֽ����鹹���ַ�������
+        byte[] byteArray = {72, 101, 108, 108, 111}; // ��Ӧ�ַ� "Hello"
+        String str = new String(byteArray);
+        System.out.println("�ַ�������: " + str); // ��� "Hello"
+    }
+}

Java程序学习和训练/0033今晚十点进攻/EncryptAndDecrypt.java

@@ -1,3 +1,33 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:5d82dacc3a715d5af0e24c9e5e6e78f6a0c1f9703d2b5b0f25bf11241dfd4815
-size 1316
+public class EncryptAndDecrypt {   
+    // �����㷨
+    String encrypt(String sourceString, String password) {
+        char[] p = password.toCharArray(); // ������ת��Ϊ�ַ�����
+        int n = p.length; // ��������ij���
+        char[] c = sourceString.toCharArray(); // ��Դ�ַ���ת��Ϊ�ַ�����
+        int m = c.length; // Դ�ַ�������ij���
+        
+        // ��ÿ���ַ����м���
+        for (int k = 0; k < m; k++) {
+            int mima = c[k] + p[k % n]; // �����㷨����Դ�ַ�����ÿ���ַ�������Ķ�Ӧ�ַ����
+            c[k] = (char) mima; // �����ܺ���ַ��������
+        }
+        
+        return new String(c); // ���ؼ��ܺ���ַ��������ģ�
+    }
+    
+    // �����㷨
+    String decrypt(String sourceString, String password) {
+        char[] p = password.toCharArray(); // ������ת��Ϊ�ַ�����
+        int n = p.length; // ��������ij���
+        char[] c = sourceString.toCharArray(); // �������ַ���ת��Ϊ�ַ�����
+        int m = c.length; // ��������ij���
+        
+        // ��ÿ���ַ����н���
+        for (int k = 0; k < m; k++) {
+            int mima = c[k] - p[k % n]; // �����㷨�������ĵ�ÿ���ַ�������Ķ�Ӧ�ַ����
+            c[k] = (char) mima; // �����ܺ���ַ��������
+        }
+        
+        return new String(c); // ���ؽ��ܺ���ַ��������ģ�
+    }
+}

Java程序学习和训练/0033今晚十点进攻/Example8_8.java

@@ -1,3 +1,23 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:06436620c5748ca41b7b9b55eafaee911cd7b67c58725a4134da255bb5b71d68
-size 762
+import java.util.Scanner;
+
+public class Example8_8 {
+    public static void main(String[] args) {
+        String sourceString = "����ʮ�����";
+        EncryptAndDecrypt person = new EncryptAndDecrypt(); 
+        
+        System.out.println("�����������: " + sourceString);
+        Scanner scanner = new Scanner(System.in);
+        String password = scanner.nextLine();
+        
+        String secret = person.encrypt(sourceString, password);
+        System.out.println("����: " + secret);
+        
+        System.out.println("�����������");
+        password = scanner.nextLine();
+        
+        String source = person.decrypt(secret, password);
+        System.out.println("����: " + source);
+        
+        scanner.close();
+    }
+}

Java程序学习和训练/0034英语单词拼写训练/Untitled1 - 副本 - 副本 (2).java

@@ -1,3 +1,7 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:7aa19ca422c2fcbd62dcc475fced839bee2dcf39d9803a0daee747850055e79a
-size 104
+class  
+{
+	public static void main(String[] args) 
+	{
+		System.out.println("Hello World!");
+	}
+}