Question

我尝试做的是在使用sstream库解析时从每行的文本文件中读取。我让程序运行但是它陷入了循环。

程序：

<firebase-document path="/build the path here" data="data" ></firebase-document>
<div class="card">
  <h1>{{data.title}}</h1>
  <paper-input label="item" value="{{data.item}}"></paper-input>
</div>

的test.txt：

string date;
int time;
float amount;

ifstream testFile("test.txt");
string token;
string line;

while(!testFile.eof()) {

    while(getline(testFile,token,',')){
        line += token + ' ';
    }
    stringstream ss(line); 
    ss >> date;
    ss >> time;
    ss >> amount;

    cout << "Date: " << date << " ";
    cout << "Time: " << time << " ";
    cout << "Amount: " << amount << " ";
    cout<<endl;

    ss.clear();

}    
testFile.close();

通缉输出：

10/12/1993,0800,7.97
11/12/1993,0800,8.97

我该如何有效地制作这个？

Answer 1

不要使用eof循环。 Why is iostream::eof inside a loop condition considered wrong?
逐行读取文件。 Read file line by line
使用,作为分隔符拆分每一行的字符串。 Split a string in C++?
创建第二个和第三个字符串的std::stringstream个对象，并使用operator>>从中获取int和double个值。

Answer 2

<div class="container">
    <div class="row">
        <!--<div class="col-sm-6"><img src="images/test.png"></div><div class="col-sm-6"><span class="pull-center"><img src="images/test.png"></span></div>-->
        <div class="col-sm-12">

<nav class="col-sm-3" id="myScrollspy">
  <ul class="nav nav-pills nav-stacked">
    <li><a href="#account_register">account_register</a></li>
    <li><a href="#login_logout">login_logout</a></li>
    <li><a href="#buying_process">buying_process</a></li>

  </ul>         
      </ul>
    </li>
  </ul>
</nav>
<div class="col-sm-9">
  <div id="account_register">    
    <h1>buying_process</h1>
    <p>Try to scroll this section and look at the navigation list while scrolling!</p>
  </div>

  <div id="login_logout">  <hr>
    <h1>login_logout</h1>
    <p>Try to scroll this section and look at the navigation list while scrolling!</p>
  </div>

  <div id="buying_process">  <hr>   
    <h1>buying_process</h1>
    <p>Try to scroll this section and look at the navigation list while scrolling!</p>
  </div>




</div>

您应该使用#include <algorithm> #include <fstream> #include <iomanip> #include <iostream> #include <sstream> #include <string> using namespace std; int main() { ifstream testFile("testdates.txt"); string line; while(getline(testFile, line)){ string date; int time; float amount; std::replace(line.begin(), line.end(), ',', ' '); stringstream ss(line); ss >> date; ss >> time; ss >> amount; cout << "Date: " << date << " "; cout << "Time: " << std::setfill('0') << std::setw(4) << time << " "; cout << "Amount: " << amount << " "; cout << '\n'; } }逐行阅读。您应该检查此返回值以了解何时退出（不是getline）。然后，您可以用空格替换所有逗号，并使用现有的流解析代码来读取值。

请注意!eof和ss.clear()不是必需的，因为每次迭代都会重新创建testFile.close()，并且在其析构函数中关闭ss。

是否可以迭代文本文件行并使用stringstream来解析每一行？

2 个答案: