不兼容的类型 - 是因为数组已经是一个指针了？ [英] Incompatible types - is it because an array is already a pointer?

问题描述

在下面的代码中，我创建一个基于书籍结构的对象，并且它拥有多个书籍我设置是一个数组（被定义/启动的对象）。但是，每当我去测试我的指针知识（实践帮助），并试图做一个指针指向创建的对象，它给我的错误：

In the below code I create an object based off of the books structure, and to have it hold multiple "books" I set is an array (the object that is defined/initiated, that is). However, whenever I went to test my knowledge of pointers (the practice helps) and attempted to make a pointer that points to the created object, it gives me the error:

C：\Users\Justin\Desktop\Project\wassuip\main.cpp | 18 |错误：将书籍分配给books * [4]时不兼容的类型| *

C:\Users\Justin\Desktop\Project\wassuip\main.cpp|18|error: incompatible types in assignment of 'books' to 'books* [4]'|*

我可以问，这是因为对象book_arr []已经被认为是一个指针，因为它是一个数组？感谢（新到C ++，只想验证）。

May I ask, is this because the object book_arr[] is already considered a pointer as it's an array? Thanks (new to C++ and just want to verify).

#include <iostream>
#include <vector>
#include <sstream>

#define NUM 4

using namespace std;

struct books {
    float price;
    string name;
    int rating;
} book_arr[NUM];

int main()
{
    books *ptr[NUM];
    ptr = &book_arr[NUM];

    string str;

    for(int i = 0; i < NUM; i++){
        cout << "Enter book name: " << endl;
        cin >> ptr[i]->name;
        cout << "Enter book price: " << endl;
        cin >> str;
        stringstream(str) << ptr[i]->price;
        cout << "Enter book rating: " << endl;
        cin >> str;
        stringstream(str) << ptr[i]->rating;
    }

    return 0;
}

* 答案后的新代码（无错误）*

#include <iostream>
#include <vector>
#include <sstream>

#define NUM 4

using namespace std;

/* structures */
struct books {
    float price;
    string name;
    int rating;
} book[NUM];

/* prototypes */
void printbooks(books book[NUM]);

int main()
{
    string str;

    books *ptr = book;

    for(int i = 0; i < NUM; i++){
        cout << "Enter book name: " << endl;
        cin >> ptr[i].name;
        cout << "Enter book price: " << endl;
        cin >> str;
        stringstream(str) << ptr[i].price;
        cout << "Enter book rating: " << endl;
        cin >> str;
        stringstream(str) << ptr[i].rating;
    }

    return 0;
}

void printbooks(books book[NUM]){
    for(int i = 0; i < NUM; i++){
        cout << "Title: \t" << book[i].name << endl;
        cout << "Price: \t$" << book[i].price << endl;
        cout << "Racing: \t" << book[i].rating << endl;
    }
}

推荐答案

img src =http://i.imgur.com/Zwhdn.gifalt =数组不是指针>

请参阅如何在C ++中使用数组？详细信息。

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