深入解析面向对象编程在Java中的应用小结

class Person {
    // 属性（成员变量）
    String name;
    int age;
    // 构造方法（用来初始化对象）
    Person(String name, int age) {
        this.name = name;
        this.age = age;
    }
    // 方法（行为）
    void introduce() {
        System.out.println("Hi, my name is " + name + " and I am " + age + " years old.");
    }
}
public class Main {
    public static void main(String[] args) {
        // 创建对象
        Person person = new Person("JuMao", 20);
        // 调用方法
        person.introduce();
    }
}

class BankAccount {
    private double balance; // 私有属性
    // 公共方法
    public void deposit(double amount) {
        if (amount > 0) {
            balance += amount;
        }
    }
    public void withdraw(double amount) {
        if (amount > 0 && balance >= amount) {
            balance -= amount;
        }
    }
    public double getBalance() {
        return balance;
    }
}

class Animal {
    void eat() {
        System.out.println("This animal is eating.");
    }
}
class Dog extends Animal {
    void bark() {
        System.out.println("The dog is barking.");
    }
    // 重写父类的方法
    @Override
    void eat() {
        System.out.println("The dog is eating bones.");
    }
}
public class Main {
    public static void main(String[] args) {
        Animal animal = new Animal();
        animal.eat(); // 输出: This animal is eating.
        Dog dog = new Dog();
        dog.eat(); // 输出: The dog is eating bones.
        dog.bark(); // 输出: The dog is barking.
    }
}

class Shape {
    void draw() {
        System.out.println("Drawing a shape.");
    }
}
class Circle extends Shape {
    @Override
    void draw() {
        System.out.println("Drawing a circle.");
    }
}
class Rectangle extends Shape {
    @Override
    void draw() {
        System.out.println("Drawing a rectangle.");
    }
}
public class Main {
    public static void main(String[] args) {
        Shape shape1 = new Circle();
        Shape shape2 = new Rectangle();
        shape1.draw(); // 输出: Drawing a circle.
        shape2.draw(); // 输出: Drawing a rectangle.
    }
}