Question

我对C ++很陌生，尽管我曾经简单地使用过C＃和一些web-dev语言。我有一个数据库存储为已知位置的.txt文件。 .txt文件的第一行是数据库中有多少项。我有一个Struct来读取所有值，因为它们具有相同的格式。

我已经设法编写了一段代码，它将在文件中读取并给出一个有多少项的整数值，我只需要帮助将数据读入一个结构数组。

示例数据库是

3

NIKEAIRS
9
36.99

CONVERSE
12
35.20

GIFT
100
0.1

我的结构是

struct Shoes{
   char Name[25];
   unsigned int Stock;
   double Price;
};

我读取项目数量的代码是

#include <iostream>
#include <fstream>
#include <string>
using namespace std;


int main ()
{
    char UserInput;

    string NumOfItems; //this will contain the data read from the file
    ifstream Database("database.txt"); //opening the file.
    if (Database.is_open()) //if the file is open
    {
        int numlines;
        getline (Database,NumOfItems);
        numlines=atoi(NumOfItems.c_str());
        cout<<numlines;
    }
    else cout << "Unable to open file"; //if the file is not open output
    cin>>UserInput;
    return 0;
}

我是否可以提供一些有关如何继续的建议。

Answer 1

这样的事情怎么样？我知道有更有效的方法来做到这一点，但至少这应该让你开始朝着正确的方向前进。干杯！

#include <iostream>
#include <fstream>
#include <string>

#include <vector>
#include <stdlib.h>

using namespace std;

struct Shoes {
    char Name[25];
    unsigned int Stock;
    double Price;
};

vector<Shoes> ShoeList;

static Shoes readShoe(std::ifstream& fs)
{
    char buffer[200];               //  temporary buffer
    Shoes s;

    fs.getline(buffer, sizeof(buffer));     // newline
    fs.getline(s.Name, sizeof(buffer));     // name
    fs.getline(buffer, sizeof(buffer));     // amt in stock
    s.Stock=atoi(buffer);
    fs.getline(buffer, sizeof(buffer));     // price
    s.Price=strtod(buffer, 0);

    return s;
}

int main ()
{
    char UserInput;

    string NumOfItems; //this will contain the data read from the file
    ifstream Database("database.txt"); //opening the file.
    if (Database.is_open()) //if the file is open
    {
        int numlines;
        getline (Database,NumOfItems);
        numlines=atoi(NumOfItems.c_str());
        cout<<numlines;

    cout << endl;
    for(int i=0; i < numlines; ++i)
    {
        Shoes s = readShoe(Database);
        ShoeList.push_back(s);
        cout << "Added (Name=" << s.Name << "," << s.Stock << "," << s.Price << ") to list." << endl;
    }

    }
    else cout << "Unable to open file"; //if the file is not open output

    cin>>UserInput;

    return 0;
}

Answer 2

for (int i = 0; i < numlines; ++i)
{
 Shoes sh();
 Database >> sh.Name >> sh.Stock >> sh.price;
 //do something with sh (add it to a list or a array for example
}

读取.txt以使用有限数量的项目进行结构化

2 个答案: