小编use*_*404的帖子

如果我有班车:

public class Car {

    int weight;
    Car(){}

    public Car(int weight) {
        this.weight = weight;
    }
}

还有另一个继承自Car的轿车:

 public class Sedan extends Car { 

     public Sedan(int weight) {
         super(weight);
     }
 }

和继承自汽车的第三级吉普车:

public class Jeep extends Car {

    public Jeep(int weight) {
        super(weight);
    }
} 

我怎么能这样说,当我说 Car mercedes = new Car(5000);

构造函数创建一个new Jeep或一个new Sedan取决于给定的权重:if( weight>3000),创建一个吉普车mercedes=new Jeep(weight);,否则创建一个轿车mercedes=new Sedan(weight);？