如何.txt文件复制到c进行字符数组++ [英] How to copy a .txt file to a char array in c++

问题描述

我试着去整个.txt文件复制到一个字符数组。我的code ++工程，但它留下了空白。因此，举例来说，如果我的.txt文件上写着我爱派，我把它复制到myarray的，如果我用一个for循环我得到ILikePie

Im trying to copy a whole .txt file into a char array. My code works but it leaves out the white spaces. So for example if my .txt file reads "I Like Pie" and i copy it to myArray, if i cout my array using a for loop i get "ILikePie"

下面是我的code

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

int main () 
{
  int arraysize = 100000;
  char myArray[arraysize];
  char current_char;
  int num_characters = 0;
  int i = 0;

  ifstream myfile ("FileReadExample.cpp");

     if (myfile.is_open())
        {
          while ( !myfile.eof())
          {
                myfile >> myArray[i];
                i++;
                num_characters ++;
          }      

 for (int i = 0; i <= num_characters; i++)
      {

         cout << myArray[i];
      } 

      system("pause");
    }

有什么建议？ ：/

any suggestions? :/

推荐答案

通过

myfile >> myArray[i]; 

你是哪个字跳绳导致的空间读取文件字。

you are reading file word by word which causes skipping of the spaces.

您可以读取整个文件与字符串

You can read entire file into the string with

std::ifstream in("FileReadExample.cpp");
std::string contents((std::istreambuf_iterator<char>(in)), 
    std::istreambuf_iterator<char>());

然后你可以使用 contents.c_str（）来获得字符数组。

这是如何工作

的std ::字符串有一系列构造副本区间[first的字符序列，最后）注意，它不会复制去年，以相同的顺序：

std::string has range constructor that copies the sequence of characters in the range [first,last) note that it will not copy last, in the same order:

template <class InputIterator>
  string  (InputIterator first, InputIterator last);

的std :: istreambuf_iterator 迭代器是读取流缓冲区连续元素输入迭代器。

std::istreambuf_iterator iterator is input iterator that read successive elements from a stream buffer.

std::istreambuf_iterator<char>(in)

将在为我们的 ifstream的迭代器（文件的开头），如果不传递任何参数的构造，它会创建最终OF-流迭代器（最后一个位置）：

will create iterator for our ifstream in (beginning of the file), and if you don't pass any parameters to the constructor, it will create end-of-stream iterator (last position):

默认构造的std :: istreambuf_iterator被称为尾流的迭代器。当一个有效的std :: istreambuf_iterator到达底层流的末尾，就等于尾流的迭代器。解引用或递增进一步调用未定义的行为。

The default-constructed std::istreambuf_iterator is known as the end-of-stream iterator. When a valid std::istreambuf_iterator reaches the end of the underlying stream, it becomes equal to the end-of-stream iterator. Dereferencing or incrementing it further invokes undefined behavior.

因此​​，这将复制的所有字符，从该文件中的第一起，直到下一个字符是流的末尾

So, this will copy all characters, starting from the first in the file, until the next character is end of the stream.

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