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src/main/java/smy/javastudy/GrammarPractice.java

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+package smy.javastudy;
+
+public class GrammarPractice {
+    public void Exchange(String input){
+        switch (input){
+            case "刘道熙":
+                System.out.println("是畜生");
+                break;
+            case "唐伟":
+                System.out.println("是大帅比");
+                break;
+            default:
+                System.out.println("不知道");
+                break;
+        }
+    }
+}

src/main/java/smy/javastudy/JavaBasicDataType.java

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+package smy.javastudy;
+
+public class JavaBasicDataType {
+    public int integerType = 100; //整数类型
+    public float floatType = 3.14f; //单精度浮点类型
+    public double doubleType = 3.141592653589793; //双精度浮点类型
+    public char charType = 'A'; //字符类型
+    public boolean booleanType = true; //布尔类型
+    public String stringType = "Hello, Java!"; //字符串类型
+    public long longType = 123456789L; //长整型
+    public short shortType = 32000; //短整型
+    public byte byteType = 100; //字节型
+
+    public void displayDataTypes() {
+        System.out.println("==================================================");
+        System.out.println("整数类型 (int): " + integerType);
+        System.out.println("单精度浮点类型 (float): " + floatType);
+        System.out.println("双精度浮点类型 (double): " + doubleType);
+        System.out.println("字符类型 (char): " + charType);
+        System.out.println("布尔类型 (boolean): " + booleanType);
+        System.out.println("字符串类型 (String): " + stringType);
+        System.out.println("长整型 (long): " + longType);
+        System.out.println("短整型 (short): " + shortType);
+        System.out.println("字节型 (byte): " + byteType);
+        System.out.println("==================================================");
+    }
+
+    public void ShowDataTypesInfo() {
+        System.out.println("==================================================");
+        System.out.println("基本类型：byte 二进制位数："+Byte.SIZE);
+        System.out.println("包装类：java.lang.Byte");
+        System.out.println("最小值：Byte.MIN_VALUE="+Byte.MIN_VALUE);
+        System.out.println("最大值：Byte.MAX_VALUE="+Byte.MAX_VALUE);
+        System.out.println();
+
+        System.out.println("基本类型：short 二进制位数："+Short.SIZE);
+        System.out.println("包装类：java.lang.Short");
+        System.out.println("最小值：Short.MIN_VALUE="+Short.MIN_VALUE);
+        System.out.println("最大值：Short.Max_Value="+Short.MAX_VALUE);
+        System.out.println();
+
+        System.out.println("基本类型：int 二进制位数："+Integer.SIZE);
+        System.out.println("包装类：java.lang.Integer");
+        System.out.println("最小值：Integer.MIN_VALUE="+Integer.MIN_VALUE);
+        System.out.println("最大值：Integer.Max_Value="+Integer.MAX_VALUE);
+        System.out.println();
+
+        System.out.println("基本类型：long 二进制位数："+Long.SIZE);
+        System.out.println("包装类：java.lang.Long");
+        System.out.println("最小值：Long.MIN_VALUE="+Long.MIN_VALUE);
+        System.out.println("最大值：Long.Max_Value="+Long.MAX_VALUE);
+        System.out.println();
+
+        System.out.println("基本类型：float 二进制位数："+Float.SIZE);
+        System.out.println("包装类：java.lang.Float");
+        System.out.println("最小值：Float.MIN_VALUE="+Float.MIN_VALUE);
+        System.out.println("最大值：Float.Max_Value="+Float.MAX_VALUE);
+        System.out.println();
+
+        System.out.println("基本类型：double 二进制位数："+Double.SIZE);
+        System.out.println("包装类：java.lang.Double");
+        System.out.println("最小值：Double.MIN_VALUE="+Double.MIN_VALUE);
+        System.out.println("最大值：Double.Max_Value="+Double.MAX_VALUE);
+        System.out.println();
+
+        System.out.println("基本类型：char 二进制位数："+Character.SIZE);
+        System.out.println("包装类：java.lang.Character");
+        System.out.println("最小值：Character.MIN_VALUE="+(int)Character.MIN_VALUE);
+        System.out.println("最大值：Character.Max_Value="+(int)Character.MAX_VALUE);
+
+        System.out.println("==================================================");
+
+    }
+}

src/main/java/smy/javastudy/Main.java

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+package smy.javastudy;
+
+
+
+public class Main {
+    final double PI = 3.14159;
+    int decimal = 100;
+    int octal = 0144;
+    int hexa = 0x64;
+
+    //项目唯一主函数
+    public static void main(String[] args) {
+        //TIP 当文本光标位于高亮显示的文本处时按 <shortcut actionId="ShowIntentionActions"/>
+        // 查看 IntelliJ IDEA 建议如何修正。
+        System.out.printf("Hello and welcome!\n");
+        Main main = new Main();
+        main.testHuHangTao();
+
+        JavaBasicDataType dataType = new JavaBasicDataType();
+        dataType.ShowDataTypesInfo();
+
+        GrammarPractice grammarPractice = new GrammarPractice();
+        grammarPractice.Exchange("刘道熙");
+        grammarPractice.Exchange("唐伟");
+        grammarPractice.Exchange("树萌芽");
+
+        NumberAndMathDemo demo = new NumberAndMathDemo();
+        demo.numberClassUsage();
+        demo.mathClassUsage();
+    }
+
+    public void testHuHangTao(){
+        SWPUStudent HuHangTao = new SWPUStudent("胡航滔", 20, "2024520541", "网络工程", 3.8, "hht@stu.swpu.edu.cn", "12345678901", "四川省广安市", "男");
+        HuHangTao.ShowInfo();
+
+        HuHangTao.setGpa(4.5);
+        HuHangTao.setEmail(HuHangTao.getStudentID() + "@stu.swpu.edu.cn");
+        HuHangTao.setPhoneNumber("18782345678");
+        HuHangTao.ShowInfo();
+
+
+    }
+}

src/main/java/smy/javastudy/NumberAndMathDemo.java

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+package smy.javastudy;
+
+import java.math.BigDecimal;
+import java.math.BigInteger;
+
+public class NumberAndMathDemo {
+
+    public void numberClassUsage() {
+        System.out.println("=========================Number类的用法=========================");
+
+        // Number 是一个抽象类，其子类包括 Integer、Double、Float 等。
+        // 我们可以用它来持有任何数字类型。
+        Number num1 = 123;
+        Number num2 = 456.78;
+
+        System.out.println("num1 是: " + num1 + "，类型是 " + num1.getClass().getName());
+        System.out.println("num2 是: " + num2 + "，类型是 " + num2.getClass().getName());
+
+        // xxxValue() 方法用于转换为基本数据类型
+        System.out.println("num1 作为 int: " + num1.intValue());
+        System.out.println("num1 作为 double: " + num1.doubleValue());
+        System.out.println("num2 作为 int: " + num2.intValue()); // 注意：这会截断小数部分
+        System.out.println("num2 作为 long: " + num2.longValue());
+        System.out.println("num2 作为 float: " + num2.floatValue());
+        System.out.println("num2 作为 byte: " + num2.byteValue());
+        System.out.println("num2 作为 short: " + num2.shortValue());
+
+        // compareTo() 方法 (来自 Comparable 接口, 由 Number 的子类实现)
+        Integer int1 = 100;
+        Integer int2 = 200;
+        System.out.println("比较 100 和 200: " + int1.compareTo(int2)); // 如果小于则为-1，如果等于则为0，如果大于则为1
+
+        // equals() 方法
+        Double double1 = 123.45;
+        Double double2 = 123.45;
+        System.out.println("用 equals() 比较 123.45 和 123.45: " + double1.equals(double2));
+
+        // 使用 BigInteger 和 BigDecimal 处理非常大的数字
+        BigInteger bigInt = new BigInteger("12345678901234567890");
+        BigDecimal bigDecimal = new BigDecimal("1234567890.0987654321");
+        System.out.println("BigInteger: " + bigInt);
+        System.out.println("BigDecimal: " + bigDecimal);
+
+        // 大数的算术运算
+        BigInteger bigIntSum = bigInt.add(new BigInteger("1"));
+        System.out.println("BigInteger 的和: " + bigIntSum);
+        BigDecimal bigDecimalProduct = bigDecimal.multiply(new BigDecimal("2.5"));
+        System.out.println("BigDecimal 的积: " + bigDecimalProduct);
+        System.out.println("=========================Number类的用法=========================");
+    }
+
+    public void mathClassUsage() {
+        System.out.println("\n=========================Math类的用法=========================");
+
+        double x = 45.6;
+        double y = -78.9;
+        double angle = 45.0;
+
+        // 基本算术方法
+        System.out.println(y + " 的绝对值是: " + Math.abs(y));
+        System.out.println(x + " 的向上取整是: " + Math.ceil(x)); // 向上取整
+        System.out.println(x + " 的向下取整是: " + Math.floor(x)); // 向下取整
+        System.out.println(x + " 的四舍五入是: " + Math.round(x)); // 四舍五入到最近的整数
+        System.out.println(x + " 和 " + y + " 的最大值是: " + Math.max(x, y));
+        System.out.println(x + " 和 " + y + " 的最小值是: " + Math.min(x, y));
+
+        // 指数和对数函数
+        System.out.println("e^2 是: " + Math.exp(2));
+        System.out.println("10 的自然对数是: " + Math.log(10));
+        System.out.println("100 的以10为底的对数是: " + Math.log10(100));
+        System.out.println("2^3 是: " + Math.pow(2, 3));
+        System.out.println("16 的平方根是: " + Math.sqrt(16));
+
+        // 三角函数
+        double radians = Math.toRadians(angle);
+        System.out.println(angle + " 度的正弦值是: " + Math.sin(radians));
+        System.out.println(angle + " 度的余弦值是: " + Math.cos(radians));
+        System.out.println(angle + " 度的正切值是: " + Math.tan(radians));
+        System.out.println("将 " + radians + " 弧度转换为度: " + Math.toDegrees(radians));
+
+        // 随机数生成
+        // Math.random() 返回一个大于等于 0.0 且小于 1.0 的 double 值
+        System.out.println("一个随机数: " + Math.random());
+        // 获取一个范围内的随机整数，例如 [1, 10]
+        int randomInt = (int) (Math.random() * 10) + 1;
+        System.out.println("一个 1 到 10 之间的随机整数: " + randomInt);
+        System.out.println("\n=========================Math类的用法=========================");
+    }
+}

src/main/java/smy/javastudy/SWPUStudent.java

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+package smy.javastudy;
+
+public class SWPUStudent {
+    private String name; //学生姓名
+    private int age; //学生年龄
+    private String studentID; //学号
+    private String major; //专业
+    private double gpa; //绩点
+    private String email; //电子邮件
+    private String phoneNumber; //电话号码
+    private String address; //住址
+    private String gender; //性别
+
+    //学生类构造函数
+    public SWPUStudent(String name, int age, String studentID, String major, double gpa, String email, String phoneNumber, String address, String gender) {
+        this.name = name;
+        this.age = age;
+        this.studentID = studentID;
+        this.major = major;
+        this.gpa = gpa;
+        this.email = email;
+        this.phoneNumber = phoneNumber;
+        this.address = address;
+        this.gender = gender;
+    }
+
+    //展示学生基本信息
+    public void ShowInfo() {
+        System.out.println("==================================");
+        System.out.println("西南石油大学学生信息：");
+        System.out.println("姓名: " + name);
+        System.out.println("年龄: " + age);
+        System.out.println("学号: " + studentID);
+        System.out.println("专业: " + major);
+        System.out.println("绩点: " + gpa);
+        System.out.println("电子邮件: " + email);
+        System.out.println("电话号码: " + phoneNumber);
+        System.out.println("住址: " + address);
+        System.out.println("性别: " + gender);
+        System.out.println("==================================");
+    }
+
+
+//======================对学生属性进行封装==================================
+
+    //姓名
+    public String getName() {
+        return name;
+    }
+
+    public String setName(String name) {
+        return this.name = name;
+    }
+
+
+    //年龄
+    public int getAge() {
+        return age;
+    }
+
+    public void setAge(int age) {
+        this.age = age;
+    }
+
+
+    //学生ID
+    public String getStudentID() {
+        return studentID;
+    }
+
+    public void setStudentID(String studentID) {
+        this.studentID = studentID;
+    }
+
+
+    //专业
+    public String getMajor() {
+        return major;
+    }
+
+    public void setMajor(String major) {
+        this.major = major;
+    }
+
+
+    //学分绩点
+    public double getGpa() {
+        return gpa;
+    }
+
+    public void setGpa(double gpa) {
+        this.gpa = gpa;
+    }
+
+
+    //邮箱
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+
+
+    //电话号码
+    public String getPhoneNumber() {
+        return phoneNumber;
+    }
+
+    public void setPhoneNumber(String phoneNumber) {
+        this.phoneNumber = phoneNumber;
+    }
+
+
+    //家庭住址
+    public String getAddress() {
+        return address;
+    }
+
+    public void setAddress(String address) {
+        this.address = address;
+    }
+
+
+    //年龄
+    public String getGender() {
+        return gender;
+    }
+
+    public void setGender(String gender) {
+        this.gender = gender;
+    }
+//======================对学生属性进行封装==================================
+
+
+}

src/main/java/smy/javastudy/TestNumberClass.java

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+package smy.javastudy;
+import java.lang.Number;
+
+public class TestNumberClass {
+
+    //基本类型转换
+    public void typeConversion(){
+        Number num1 = 1234.56;
+        System.out.println(num1);
+        System.out.println(num1.getClass());
+        System.out.println(num1.intValue());
+        System.out.println(num1.longValue());
+        System.out.println(num1.doubleValue());
+        System.out.println(num1.floatValue());
+        System.out.println(num1.byteValue());
+    }
+
+    //数值比较
+    public void compareNum(){
+        Integer x = 10;
+        Double y = 10.0;
+        System.out.println(x.doubleValue()==y.doubleValue());
+    }
+
+    //处理大数
+    //public
+}