Java中的this关键字详解：深入理解与应用

class Person {
    private String name;
    private int age;
    // 构造方法
    public Person(String name, int age) {
        this.name = name;  // this指代当前对象的成员变量
        this.age = age;    // this指代当前对象的成员变量
    }
    // 成员方法
    public void introduce() {
        System.out.println("My name is " + this.name + " and I am " + this.age + " years old.");
    }
}
public class Main {
    public static void main(String[] args) {
        Person person = new Person("Alice", 25);
        person.introduce();
    }
}

class Rectangle {
    private int width;
    private int height;
    // 构造方法，参数与成员变量同名
    public Rectangle(int width, int height) {
        this.width = width;   // 使用this区分成员变量与方法参数
        this.height = height; // 使用this区分成员变量与方法参数
    }
    public void displayArea() {
        System.out.println("Area: " + (this.width * this.height));
    }
}
public class Main {
    public static void main(String[] args) {
        Rectangle rect = new Rectangle(10, 5);
        rect.displayArea();
    }
}

class Car {
    private String brand;
    private int year;
    // 默认构造方法
    public Car() {
        this("Unknown", 2020);  // 使用this()调用另一个构造方法
    }
    // 带参数的构造方法
    public Car(String brand, int year) {
        this.brand = brand;
        this.year = year;
    }
    public void displayInfo() {
        System.out.println("Brand: " + this.brand + ", Year: " + this.year);
    }
}
public class Main {
    public static void main(String[] args) {
        Car car1 = new Car();
        car1.displayInfo(); // 输出默认信息
        Car car2 = new Car("Toyota", 2023);
        car2.displayInfo(); // 输出指定信息
    }
}

class Employee {
    private String name;
    public Employee(String name) {
        this.name = name;
    }
    // 接受当前对象作为参数的方法
    public void displayEmployeeInfo(Employee employee) {
        System.out.println("Employee Name: " + employee.name);
    }
    public void passObject() {
        // 使用this将当前对象传递给方法
        displayEmployeeInfo(this);
    }
}
public class Main {
    public static void main(String[] args) {
        Employee emp = new Employee("John");
        emp.passObject();
    }
}