diff --git a/W3/TestCar.java b/W3/TestCar.java
new file mode 100644
index 0000000..7063786
--- /dev/null
+++ b/W3/TestCar.java
@@ -0,0 +1,138 @@
+package com.rental;
+
+public class TestCar {
+    public static void main(String[] args) {
+        // 创建3辆车
+        Car car1 = new Car("京A12345", "丰田", "凯美瑞", 500.0);
+        Car car2 = new Car("沪B67890", "大众", "帕萨特");
+        Car car3 = new Car("粤C54321", "宝马", "3系", 800.0);
+
+        // 输出车辆信息
+        System.out.println("=====车辆信息=====");
+        car1.displayInfo();
+        car2.displayInfo();
+        car3.displayInfo();
+
+        // 测试租车还车
+        System.out.println("=====租赁测试=====");
+        car1.rentCar();
+        car1.rentCar();
+        car1.returnCar();
+        car1.returnCar();
+
+        // 计算5天租金
+        System.out.println("\n=====5天租金=====");
+        double money = car3.calculateRent(5);
+        System.out.println("5天总租金：" + money);
+
+        // 测试非法租金
+        System.out.println("\n=====测试非法日租金=====");
+        car2.setDailyRent(-100);
+
+        // 车辆总数
+        System.out.println("\n=====总车辆数=====");
+        System.out.println("总车辆数：" + Car.getTotalCars());
+    }
+}
+
+// Car 类写在同一个文件里
+class Car {
+    private final String licensePlate;
+    private String brand;
+    private String model;
+    private double dailyRent;
+    private boolean isRented;
+
+    private static int totalCars = 0;
+
+    // 全参构造
+    public Car(String licensePlate, String brand, String model, double dailyRent) {
+        this.licensePlate = licensePlate;
+        this.brand = brand;
+        this.model = model;
+        if (dailyRent > 0) {
+            this.dailyRent = dailyRent;
+        } else {
+            this.dailyRent = 300;
+            System.out.println("日租金非法，使用默认300元");
+        }
+        this.isRented = false;
+        totalCars++;
+    }
+
+    // 三参构造
+    public Car(String licensePlate, String brand, String model) {
+        this(licensePlate, brand, model, 300.0);
+    }
+
+    public String getLicensePlate() {
+        return licensePlate;
+    }
+
+    public String getBrand() {
+        return brand;
+    }
+
+    public void setBrand(String brand) {
+        this.brand = brand;
+    }
+
+    public String getModel() {
+        return model;
+    }
+
+    public void setModel(String model) {
+        this.model = model;
+    }
+
+    public double getDailyRent() {
+        return dailyRent;
+    }
+
+    public void setDailyRent(double dailyRent) {
+        if (dailyRent > 0) {
+            this.dailyRent = dailyRent;
+        } else {
+            System.out.println("设置失败：日租金必须大于0");
+        }
+    }
+
+    public boolean isRented() {
+        return isRented;
+    }
+
+    public void rentCar() {
+        if (isRented) {
+            System.out.println("车辆已租出，无法再次租用");
+        } else {
+            isRented = true;
+            System.out.println("租车成功");
+        }
+    }
+
+    public void returnCar() {
+        if (!isRented) {
+            System.out.println("车辆未被租用，无需归还");
+        } else {
+            isRented = false;
+            System.out.println("还车成功");
+        }
+    }
+
+    public double calculateRent(int days) {
+        return dailyRent * days;
+    }
+
+    public void displayInfo() {
+        System.out.println("车牌号：" + licensePlate);
+        System.out.println("品牌：" + brand);
+        System.out.println("型号：" + model);
+        System.out.println("日租金：" + dailyRent);
+        System.out.println("状态：" + (isRented ? "已租出" : "可租"));
+        System.out.println("-------------------");
+    }
+
+    public static int getTotalCars() {
+        return totalCars;
+    }
+}
\ No newline at end of file
diff --git a/W3/car实验报告.pdf b/W3/car实验报告.pdf
new file mode 100644
index 0000000..01f860a
Binary files /dev/null and b/W3/car实验报告.pdf differ