Question

对于我的程序，我们应该读取一个文本文件并将其打印到屏幕上。在文本文件中，消息可能如下所示：

#email
mailservice
birdman
Intro 
Hello Birdman! Welcome!
#email
Frank
birdman
Hello
Hello Birdman, how are you?

我需要跳过#email，以便打印出来：

From: mailservice
To: birdman
Subject: Intro 
Message: Birdman! Welcome!

From: Frank
To: birdman
Subject: Hello
Message:Hello Birdman, how are you?

这是我的代码：

std::string filename1 = GetInboxFile(username);
std::ifstream fin(filename1);
std::string word;
std::cout << "\n";

std::string formatted = FormatEmailString("From: ", "To: ", "Subject: ", "Message: ");
//FormatEmailString is a function

std::cout << formatted;

while (fin.eof() == false)
{

    std::string line = GetLine(fin);

    if (fin.eof() == false)
    {

        std::cout << line << std::endl;

    }//END IF STATEMENT

}//END WHILE LOOP

std::cout << std::endl;
fin.close();

Answer 1

while (fin)
{
    std::string line = GetLine(fin);

    if (fin) // @DietmarKühl: checking if the input was successful 
    {

        // if (line.find("#email") != std::string::npos) 
        if(line == "#email\n") 
        {
             line = "\n"; // you want a empty line instead 
             // continue; // you could use continue to simply skip it
        }

        std::cout << line << std::endl;    
    }
}

Answer 2

如果输入文件只包含有效数据，而我们不需要检查它，那么我们可以按如下方式获得正确的输出：

while (getline(fin, lineFromFile)) {

    if (lineFromFile.find("#email") < 40000) {
        getline(fin, lineFromFile);
        cout<<"From: "<<lineFromFile<<endl;
        getline(fin, lineFromFile);
        cout<<"To: "<<lineFromFile<<endl;
        getline(fin, lineFromFile);
        cout<<"Subject: "<<lineFromFile<<endl;
        getline(fin, lineFromFile);
        cout<<"Message: "<<lineFromFile<<endl<<endl;
    }
}

使用getfile跳过一行

2 个答案: