Question

我有一个文本文件 - ＆gt; info.txt，其中包含以下ID，游戏，金额

info.txt

1,left4dead,50
2,warcraft3,60

我知道如何使用我的代码如下所示的向量提取细节。

stock.h

#ifndef stock_stock_h
#define stock_stock_h
#include <iostream>

class  stock  {    
public: 
  stock() {
     columnOneText = " ";
     columnTwoText  = " ";
}

stock(std::string columnOneText,
      std::string columnTwoText
);

std::string getColumnOne();
std::string getColumnTwo();

void setItemId(std::string columnOneText);
void setItemDescription(std::string columnTwoText);

private:
  std::string columnOneText, columnTwoText;
};    
#endif

main.cpp

#include "stock.h"
#include <iostream>
#include <string>
#include <fstream>
#include <sstream>
#include <vector>
using namespace std;
stock::stock(string columnOneText,
         string columnTwoText)
{
   setItemId(columnOneText);
   setItemDescription(columnTwoText);
};
 string stock::getColumnOne()    {
   return columnOneText; 
 }
string stock::getColumnTwo()  {
   return columnTwoText;
}
void stock::setItemId(string columnOneText)    {
  this->columnOneText = columnOneText;
}
void stock::setItemDescription(std::string columnTwoText) {
  this->columnTwoText = columnTwoText;
}

int main(){
  vector<stock> itemDetails;
  string line;
  string columnOneText;
  string columnTwoText;
  ifstream readFile("info.txt");

  while(getline(readFile,line))   {
     stringstream iss(line);
     getline(iss, columnOneText,',');
     getline(iss, columnTwoText, ',');

    //consturctor
    stock splitedColumns(columnOneText,
                         columnTwoText
                         );
    itemDetails.push_back(splitedColumns);
}
readFile.close();

cout << "this is column One in text file" << endl;
for (int i =0; i<itemDetails.size(); i++) {
    cout << itemDetails[i].getColumnOne()  << " " << endl;
}

cout << "this is column Two in text file" << endl;
for (int i =0; i<itemDetails.size(); i++) {
    cout << itemDetails[i].getColumnTwo()  << " " << endl;
}

}

我真正不知道的是如何使用数组而不是使用向量来提取细节。

我试过这个，但似乎无法正常工作

  string line;
  string columnOneText;
  string columnTwoText;
  string columnOneTextArray[7];
  while(getline(readFile,line))   {
    stringstream iss(line);
    getline(iss, columnOneText,',');
    getline(iss, columnTwoText, ',');
    for(int i=0; i<8; i++) {
       columnOneTextArray[i] = columnOneText;
       cout << columnOneTextArray[i];
   }  
}

你们可能会问我为什么要在数组中而不是使用vector来实现它，我只是好奇并探索如何使用数组来完成它。

Answer 1

除了使用向量之外，使用struct定义可以更简单的方式解决您的问题（您使用类有点过分，恕我直言）：

#include <fstream> #include <iostream> #include <cstdlib> #include <vector> #include <sstream> //this utilizes a more idiomatic naming convention as opposed to `columnX` typedef struct Stock { int id; std::string games; int amount; } Stock; //Syntactic sugar for easier output std::ostream& operator << (std::ostream& in, const Stock& stock) { in << stock.id << " " << stock.games << " " << stock.amount; return in; } int main() { std::string filename = "info.txt"; std::fstream ifile; std::vector <Stock> inventory; Stock stock_t;//a temporary Stock variable std::string temp; ifile.open(filename.c_str(), std::ios::in); if (!ifile.is_open()) { std::cerr << "There was a problem opening the input file: \"" << filename << "\"\n"; exit(1); } while (ifile >> temp) { std::istringstream iss(temp); int column = 0; //break each constituent line by using the comment as a delimiter: while(std::getline(iss, temp, ',')) { if (column == 0) { stock_t.id = std::atoi(temp.c_str()); } else if (column == 1) { stock_t.games = temp; } else if (column == 2) { stock_t.amount = std::atoi(temp.c_str()); } ++column; } inventory.push_back(stock_t); } for (int i = 0; i < inventory.size(); ++i) { std::cout << inventory[i] << "\n"; } ifile.close(); return 0; }

哪个输出：

1 left4dead 50 2 warcraft3 60

文本文件内容到数组

1 个答案: