我对Java很陌生，而且只有一周的学习时间，所以我仍然非常缺乏经验。我花了几天时间讨论多态，并知道我可以将父类扩展到子类，但我想知道如何让祖父类具有父类的所有属性。我做了一些研究，但没有找到我想要的东西。我正在做的是创造衣服的对象。我有一个祖父母，这是＆＃39;服装＆＃39;三个父母＆＃39; Upper_wear＆＃39;，＆＃39; Lower_wear＆＃39;和＆＃39; Shoes＆＃39;有很多孩子，比如“T恤衫”，“短裤＆＃39;和＆＃39;凉鞋＆＃39;。目前我在父母代码中的内容是：
public class Upper_wear
{
private String fabric;
private int numb_zippers;
private String draw_string;
private int numb_pockets;
private int size;
private String color;
private double length_sleeves;
private int length_shirt;
private String collar;
private String hood;
private int code;
private double price;
private String name;
Upper_wear(String fabric,int numb_zippers,String draw_string,int numb_pockets,int size,String color, double length_sleeves, int length_shirt, String collar, String hood, int code, double price, String name){
this.fabric = fabric;
this.numb_zippers = numb_zippers;
this.draw_string = draw_string;
this.numb_pockets = numb_pockets;
this.size = size;
this.color = color;
this.length_sleeves = length_sleeves;
this.length_shirt = length_shirt;
this.collar = collar;
this.hood = hood;
this.code = code;
this.price = price;
this.name = name;
}
public String get_fabric(){
return fabric;
}
public int get_numb_zippers(){
return numb_zippers;
}
public String get_draw_string(){
return draw_string;
}
public int get_numb_pockets(){
return numb_pockets;
}
public int get_size(){
return size;
}
public String get_color(){
return color;
}
public double get_length_sleeves(){
return length_sleeves;
}
public int get_length_shirt(){
return length_shirt;
}
public String get_collar(){
return collar;
}
public String get_hood(){
return hood;
}
public int get_code(){
return code;
}
public double get_price(){
return price;
}
public String get_name(){
return name;
}
}
对于孩子们的代码，我有：
public class Jacket extends Upper_wear
{
Jacket(String fabric,int numb_zippers,String draw_string,int numb_pockets,int size,String color, double length_sleeves, int length_shirt, String collar, String hood, int code, double price, String name){
super(fabric, numb_zippers, draw_string, numb_pockets, size, color, length_sleeves, length_shirt, collar, hood, code, price, name);
}
}
我之所以不提供所有变量的衣服，是因为我不想说明是不是＆＃39; Upper_wear＆＃39;有＆＃39; Shoe_laces＆＃39;这是鞋子中的一个变量。然而，我想将所有父类聚合成一个，因为当我去运行课时。在for循环中，我想列出服装的每个项目的价格，而不仅仅是父类的价格。我觉得我只能在一段时间内迭代一个父类，例如我现在所拥有的：
public class Run
{
public static void main (String[]args){
Shoes Tennis_shoes_01 = new Shoes("Canvas", 0, "yes", 10, "red and white", 0,0.5,2.5, 00001, 750.99,"Tenny shoey");
Upper_wear T_shirt_01 = new Upper_wear("Cotton", 0, "no", 0, 14, "yellow", 14.5, 15, "v-neck", "no", 00002, 990.50, "Yel-ow");)
Shoes[]In_Stock = {Tennis_shoes_01};
Upper_wear[]In_Stock_upper = {};
Lower_wear[]In_Stock_lower = {};
System.out.println("Price");
System.out.println("-------");
for(Shoes x : In_Stock){
System.out.println(x.get_name() + ": " +x.get_price());
}
for(Upper_wear x : In_Stock_upper){
System.out.println(x.get_name() + ": " + x.get_price());
}
}
我想要的更像是这样：
public class Want_run
{
public static void main(String[]args){
Clothing Tennis_shoes_01 = new Shoes("Canvas", 0, "yes", 10, "red and white", 0,0.5,2.5, 00001, 750.99,"Tenny shoey");
//Not sure if this is possible to have a class that's different than the constructor but I am looking for it to come from clothing class with properties of Shoes.
Clothing T_shirt_01 = new Upper_wear("Cotton", 0, "no", 0, 14, "yellow", 14.5, 15, "v-neck", "no", 00002, 990.50, "Yel-ow");
//So I want all properties to be in clothing but the ones that the childeren don't have I want to be just blank.ex. Upper_wear is blank on the shoe_laces.
Clothing[]In_Stock = {Tennis_shoes_01, T_shirt_01};
//I really want everything to be just in one list to iterate through but I can't currently do that with multiple parents of my knowledge.
for(Clothing x : In_Stock){
System.out.println(x.get_name() + ": " + x.get_price());
}
//this way I have only one for loop for every item,and for parents that don't have 'price' I am hoping would just not print.
}
}
所以我希望服装能够拥有＆lt; Upper_wear＆＃39;，＆lt; Lower_wear＆＃39;和＆＃39;鞋子＆＃39;的所有属性，但不能让父母拥有服装的所有属性。这样，鞋子特有的属性，我希望其他两个父母在迭代鞋子特有的方法时是空白的。我不确定我所寻找的东西是否可行。如果你无法理解我在寻找什么，我很抱歉让你感到困惑。感谢您抽出宝贵时间阅读并帮助我。
答案 0 :(得分：0)
您要做的是多态性的经典应用。你只需要澄清一些概念。
您的祖父母将包含所有儿童共有的所有属性，例如商品ID，名称，颜色，价格等。它还应包含常用功能，例如print（）函数，您需要的主要内容。
所有儿童（包括父母）都会在他们的课程中介绍他们的特定属性，例如鞋面罩/衣领和夹克内衬。他们还将根据他们的需要覆盖（提供他们自己的实现）所需的功能。所以，在你的情况下，虽然服装将有一个print（）函数，每个子类将有自己的实现，在其中它将打印所有自己的属性，如拉链，鞋带的数量。
最后，在您的主页中，您将获得一个类型服装列表，其中包含对您想要的所有类型的对象的引用。父级可以指向子类型的对象。例如，
Clothing c = new Jacket(...);
c.print(); // This will call the print() of class Jacket, not Clothing
我建议阅读动态多态性。 This link包含一个简短的介绍和一个漂亮的例子。