Improve code reusability

Improve code reusability

package car;
 
public class Car {
    String color;
    int number;
     
    void run(){
        System.out.println(color+"::"+number);
    }
}
 
class carDemo
{
    public static void main(String[] args)
    {
        Car c = new Car();
     
        show(c);
    }
    /*
     * 封装功能
     * Car c = new Car();
     * Car c1 = new Car();
     * */
    public static void show(Car cc)
    {
        cc.color = "red";
        cc.number = 4;
        cc.run();
         
    }
}