diff --git a/w4/Car.java b/w4/Car.java
new file mode 100644
index 0000000..e69de29
diff --git a/w4/TestCar.java b/w4/TestCar.java
new file mode 100644
index 0000000..c008f31
--- /dev/null
+++ b/w4/TestCar.java
@@ -0,0 +1,36 @@
+package w4;
+
+
+public class TestCar {
+    public static void main(String[] args) {
+        Car car1 = new Car("京A12345", "丰田", "凯美瑞", 450.0);
+        Car car2 = new Car("沪B67890", "大众", "帕萨特");
+        Car car3 = new Car("粤C54321", "宝马", "3系", 680.0);
+
+        System.out.println("=====初始车辆信息=====");
+        car1.displayInfo();
+        car2.displayInfo();
+        car3.displayInfo();
+
+
+        System.out.println("=====测试租车还车=====");
+        car1.rentCar();    
+        car1.rentCar();    
+        car1.returnCar();  
+        car1.returnCar();  
+        System.out.println();
+
+
+        System.out.println("=====计算5天租金=====");
+        double rent = car2.calculateRent(5);
+        System.out.println("车辆2租用5天总费用：" + rent + "元\n");
+
+
+        System.out.println("=====测试非法修改租金=====");
+        car3.setDailyRent(-100);
+        System.out.println();
+
+        System.out.println("=====车辆总数统计=====");
+        System.out.println("系统中总车辆数：" + Car.getTotalCars());
+    }
+}