C++ ofstream/ifstream读写文件demo(二十九)

1.代码示例  

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

int main(){
  //1.ofstream写入out.txt
  const char * filename = "test.txt";
  string end= "123456";
  ofstream out("out.txt");
  if(out.is_open())
  {
    /*
      "<<":插入器，向流输出数据.
      ">>":析取器，向流输出数据.
     */
    out<<"Hello World." << filename  << " "<< end << endl;
    out.close();
  }

  //2.读取out.txt
  ifstream in("out.txt");
  char buffer[200];
  if(in.is_open())
  {
    while(!in.eof())
    {
      in.getline(buffer, 100);
      cout << buffer << endl;
      out.close();
    }
  }
}