C++ New line character when outputting to a text file [closed]

问题

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.

Closed 7 years ago.

This is just a quick question. But I am trying to output data to a file, which works fine. However I am also trying to implement a new line at the appropriate point so the data, prints on individual lines.

This is how my code currently looks:

main.cpp

Writer w("Output.txt");
    w.writeString("The number of words in the script are: ");
    w.writeInt(count);
    w.writeEol();
    w.writeString("The number of Officers in the script are: ");
    w.writeInt(ofCount);
    w.writeEol();
    w.writeString("The number of Courtiers in the script are: ");
    w.writeInt(cCount);
        w.close();

Writer.cpp

void Writer::writeEol()
{
    out << "\n" << endl;
}

My code has to be implemented this way as my whole system is built around it like this.

So my question is, how would I adjust my Writer::writeEol() to add a new line to my output file?

My output file currently comes out like this:

    The number of words in the script are: 32339The number of Officers in the script are: 2The number of Courtiers in the script are: 9

Any help is greatly appreciated. :)

回答1:

Without a proper question I can just guess what you're trying to learn, so feel free to update your "question" with an actual question:

You're essentially writing two line breaks into the file, depending on the encoding (i.e. Windows or Unix line breaks) you won't see the difference:

std::endl will automatically include the correct character to create a linebreak. There's no need to write "\n" as well.

Also you don't have to pass std::endl to the stream unless you really want a line break at the specific position:

std::cout << "The result is: ";
std::cout << 50 << std::endl;

Keep in mind that depending on your editor you might not see all line breaks, e.g. Windows Notepad won't show a line break with only \n. It will instead appear as an invisible character. For actual line breaks that are accepted you'd beed \r\n. In comparison, the Open Source editor Notepad++ accepts and displays both kinds of line breaks.

回答2:

In your writeEol() method, you output both a newline (\n), and you write out a std::endl. These both have the effect of writing out a newline, which is what you want. However, the std::endl will also flush the stream, which in some cases is not desireable (it could cause slowdown if the stream is flushed after every line).

I think that your code will do what you want (albeit with two newlines), but as shuttle87 states, you only need a \n at the end of each line to achieve the desired affect.

来源：https://stackoverflow.com/questions/13415833/c-new-line-character-when-outputting-to-a-text-file