无法使用 setter 编辑存储在链表节点中的数据

Question

我的节点class:

class Node {

private:
    int orderId; //unique for each node
    Cake cake;
    Customer customerInfo;
    Node* next;

public:
    Node() {
        orderId = 0;
        next = NULL;

    }

    Node(int id, Cake ck, Customer c) {

        orderId = id;
        cake = ck;
        customerInfo = c;
    }

    int getOrderId() {
        return orderId;
    }

    Cake getCake() {

        return cake;
    }

    Customer getCustomerInfo() {
        return customerInfo;
    }

    Node* getNext() {
        return next;
    }

    void setOrderId(int id) {
        orderId = id;
    }

    void setCake(Cake ck) {

        cake = ck;
    }

    void setCustomerInfo(Customer c) {
        customerInfo = c;
    }

    void setNext(Node* n) {
        next = n;
    }

};

我的蛋糕class:

class Cake {

private:
    string code;
    string flavour;
    double weight;
    double unitPrice;
    int qty;

public:
    Cake() {
        code = "";
        flavour = "";
        weight = 0.0;
        unitPrice = 0.0;
        qty = 0;
    }

    Cake(string c, string f, double w, double p, int q) {
        code = c;
        flavour = f;
        weight = w;
        unitPrice = p;
        qty = q;
    }

    string getCode() {
        return code;
    }

...other getters

    void setCode(string c) {
        code = c;
    }

...other setters

};

编辑节点的函数：

void editOrder(SinglyLinkedList* s)
{
    int orderId, editOption, cakeOption, weightOption, qty, flavourOption;
    char next = '[=13=]';
    bool isEmpty;

    //prompt for order id
    cout << "Enter ID of order to be edited: ";
    cin >> orderId;

    //check if order exists
    if (s->checkNodeExist(orderId) != NULL) {

        Node* nodeTemp = s->checkNodeExist(orderId);

        do {

            //ask which aspect to edit
            cout << "Which aspect do you want to edit?" << endl;

            cout << left << setw(9) << "OPTION" << setw(15) << "ASPECT" << endl;
            cout << "----------------------------" << endl << endl;
            cout << left << setw(9) << "1" << setw(15) << "Code / Cake Type" << endl;
            cout << left << setw(9) << "2" << setw(15) << "Flavour" << endl;
            cout << left << setw(9) << "3" << setw(15) << "Weight" << endl;
            cout << left << setw(9) << "4" << setw(15) << "Quantity" << endl << endl;

            cout << "Enter option: ";
            cin >> editOption;

            switch (editOption) {

            case 1:
                //display cake choices & prompt for cake choice
                cout << "Choose a type of cake." << endl << endl;

                cout << left << setw(9) << "OPTION" << setw(15) << "CAKE" << setw(4) << "CODE" << endl;
                cout << "----------------------------" << endl;
                cout << left << setw(9) << "1" << setw(15) << "Pound Cake" << setw(4) << "CK01" << endl;
                cout << left << setw(9) << "2" << setw(15) << "Sponge Cake" << setw(4) << "CK02" << endl;
                cout << left << setw(9) << "3" << setw(15) << "Genoise Cake" << setw(4) << "CK03" << endl;
                cout << left << setw(9) << "4" << setw(15) << "Layer Cake" << setw(4) << "CK04" << endl;
                cout << left << setw(9) << "5" << setw(15) << "Icing Cake" << setw(4) << "CK05" << endl;
                cout << left << setw(9) << "6" << setw(15) << "Cheese Cake" << setw(4) << "CK06" << endl << endl;
                cout << "Enter option: ";
                cin >> cakeOption;

                switch (cakeOption)
                {
                case 1:
                    (*nodeTemp).getCake().setCode("CK01"); //FAIL TO UPDATE THE "CODE" USING SETTER
                    break;

例如，目标节点有一个代码为“CK02”的蛋糕对象，但现在我希望它使用setter将其设置为“CK01”。但我就是想不通为什么 setter 函数不起作用？

PS。刚开始学习 C++ 中的链表和指针，所以请放轻松。非常感谢任何帮助...谢谢：D

Answer 1

这是因为您的 getCake 方法 return 是 copy 您的 Node 对象中的蛋糕。您的 setter 然后更改了副本，但原始文件没有改变。

简单的解决方法是让您的 getter return 成为参考

Cake& getCake() {
    return cake;
}

现在getCake return是对节点中蛋糕的引用，而不是它的副本。

无法使用 setter 编辑存储在链表节点中的数据

Cannot edit data stored in a linked list's node using setter

c++

singly-linked-list