Question

我正在为我的作业构建一个Java程序，必须将产品添加到特定商店。尝试从Store类添加到ArrayList时遇到麻烦。

我的类产品如下：

class Product {

    private String pName;
    private int pPrice;
    private int pQty;

    public Product (String pName, int pPrice, int pQty) {
        this.pName = pName;
        this.pPrice = pPrice;
        this.pQty = pQty;
    }
}

和类存储如下：

class Store {

    private String storeName;
    ArrayList<Product> pList =new ArrayList<>();

    public Store() {
        String name = storeName;
        pList = new ArrayList<Product>();
    }
    public Store(String newStoreName,ArrayList<Product> newPList) {
        this.storeName = newStoreName;
        this.pList = newPList;
    }

    void setName(String storeName) {
        this.storeName = storeName;
    }
    void setProduct(Product pList) {
        pList.add(this.pList);//This return method add undefined for type Product, how to solve this error?
    }
    String getName() {
        return storeName;
    }
    ArrayList<Product> getProductList() {
        return pList;
    }
}

Answer 1

void setProduct(Product pList) {
    pList.add(this.pList);//This return method add undefined for type Product, how to solve this error?
}

应该是

void addProduct(Product product) {
    pList.add(product);
}

Answer 2

1-您应该像下面那样更改构造函数：_-

public Store(String newStoreName,ArrayList<Product> newPList) {
    this.storeName = newStoreName;
    pList.addAll(newPList);// This is standard and recommended way to add all element in list. 
}

2-更改您的setProduct方法。该运算符不能像这样工作。

void setProduct(Product pList) {
    pList.add(pList); 
}

Java方法add ArrayList对于类型<OBJECT>未定义

2 个答案: