从对象类型的角度来看,子类是否等同于他们的种族类?

我创建了3个抽象类:

班级文章:母亲班级

public abstract class Article{
    //myPrivate Var Declarations
    public Article(long reference, String title, float price, int quantity){
        this.reference  =   reference;
        this.title      =   title;
        this.price      =   price;
        this.quantity   =   quantity;
    }
}

职业电工:文章的孩子

public abstract class Electromenager extends Article{
    //myVar declarations 
    public Electromenager(long reference, String title, float price, int quantity, int power, String model) {
        super(reference, title, price, quantity);
        this.power  = power;
        this.model  = model;
    }
}

类Alimentaire:文章的另一个孩子

public abstract class Alimentaire extends Article{
    private int expire;
    public Alimentaire(long reference, String title, float price, int quantity,int expire){
        super(reference, title, price, quantity);
        this.expire = expire;
    }
}

让我们假设这些类必须是抽象的,所以基本上在主类中,我不能直接实例化它们的对象,所以我们需要做一些基本的扩展。:

class TV extends Electromenager {
    public TV(long reference, String title, float price, int quantity, int power, String model){
        super(reference,title,price,quantity,power,model);
    }
}
class EnergyDrink extends alimentaire {
    public EnergyDrink(long reference, String title, float price, int quantity,int expire){
        super(reference,title,price,quantity,expire);
    }
}

所以在这里,我的困惑开始出现了!在main()中写入时:

Article art         = new TV (145278, "OLED TV", 1000 , 1 ,220, "LG");
EnergyDrink art2    = new EnergyDrink (155278 , "Eau Miniral" , 6 , 10, 2020);

令人惊讶的是,我得到了零错误!!!!我不应该键入:

TV art          = new TV (145278, "OLED TV", 1000 , 1 ,220, "LG");
//instead of
Article art     = new TV (145278, "OLED TV", 1000 , 1 ,220, "LG");

为什么两种书写都是正确的?Java编译器如何理解这一点?