一个莱鸟的问题, 关于读文件?

towanjun

用ifstream打开读一个文件, 用完后必须得关闭吗?

FH

与上完厕所是否必须擦一擦相同

towanjun

我看了<<c++标准程序库>;>;中得一个demo,它就没关闭啊

/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/
// header files for file I/O
#include <iostream>;
#include <fstream>;

void printFileTwice (const char* filename)
{
    // open file
    std::ifstream file(filename);

    // print contents the first time
    std::cout << file.rdbuf();

    // seek to the beginning
    file.seekg(0);

    // print contents the second time
    std::cout << file.rdbuf();
}

int main (int argc, char* argv[])
{
    // print all files passed as a command-line argument twice
    for (int i=1; i<argc; ++i) {
        printFileTwice(argv);
    }
}

FH

当然不是必须的，就像上厕所一样，喜欢脏着就脏着，没人强迫。

网络痞子

原则上最好么关闭，就像水龙头的水一样，可以不关。但是最好关掉