閱讀.txt以限制數量的項目進行研究

Question

雖然我已經使用C＃和幾種web-dev語言，但我對C++相當陌生。 我有一個數據庫存儲爲一個.txt文件在一個已知的位置。 .txt文件的第一行是數據庫中的項目數。 我有一個結構來讀取所有的值，因爲它們是相同的格式。

我已經設法編寫了一段代碼，它將在文件中讀取並給出一個有多少項的整數值，我只需要幫助將數據讀入一個結構數組。

一個例子數據庫是

3 

NIKEAIRS 
9 
36.99 

CONVERSE 
12 
35.20 

GIFT 
100 
0.1 

我的結構是

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

我的代碼來讀取項目的數量爲

#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; 
} 

我可以對如何進行一些指針。

Answer 1

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 
} 

Answer 2

這樣的事情呢？我知道有更有效的方法來做到這一點，但至少這應該讓你開始朝正確的方向發展。乾杯!

#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; 
}