void readTxt(string file)
{
    ifstream infile; 
    infile.open(file.data());   //将文件流对象与文件连接起来 
    assert(infile.is_open());   //若失败,则输出错误消息,并终止程序运行 
    string s;
    while(getline(infile,s))
    {
        cout<<s<<endl;
    }
    infile.close();             //关闭文件输入流 
}

void readTxt(string file)
{
    ifstream infile; 
    infile.open(file.data());   //将文件流对象与文件连接起来 
    assert(infile.is_open());   //若失败,则输出错误消息,并终止程序运行 
    char c;
    while (!infile.eof())
    {
        infile >> c;
        cout<<c<<endl;
    }
    infile.close();             //关闭文件输入流 
}

void readTxt(string file)
{
    ifstream infile; 
    infile.open(file.data());   //将文件流对象与文件连接起来 
    assert(infile.is_open());   //若失败,则输出错误消息,并终止程序运行 
    char c;
    infile >> noskipws;
    while (!infile.eof())
    {
        infile>>c;
        cout<<c<<endl;
    }
    infile.close();             //关闭文件输入流 
}

#include<stdio.h> 
#include <iostream>
#include <fstream>
#include <cassert>
#include <string>
using namespace std;
// 一行行读
void readTxt(string file)
{
  ifstream infile;
  infile.open("data.txt");   //将文件流对象与文件连接起来 
  assert(infile.is_open());   //若失败,则输出错误消息,并终止程序运行 
  string s;
  while (getline(infile, s))
  {
    cout << s << endl;
  }
  infile.close();             //关闭文件输入流 
}
// 一字符字符读  忽略空格与回车
void readTxt2(string file)
{
  ifstream infile;
  infile.open(file.data());   //将文件流对象与文件连接起来 
  assert(infile.is_open());   //若失败,则输出错误消息,并终止程序运行 
  char c;
  while (!infile.eof())
  {
    infile >> c;
    cout << c << endl;
  }
  infile.close();             //关闭文件输入流 
}
// 一字符字符读  不忽略空格与回车
void readTxt3(string file)
{
  ifstream infile;
  infile.open(file.data());   //将文件流对象与文件连接起来 
  assert(infile.is_open());   //若失败,则输出错误消息,并终止程序运行 
  char c;
  infile >> noskipws;
  while (!infile.eof())
  {
    infile >> c;
    cout << c << endl;
  }
  infile.close();             //关闭文件输入流 
}
int main()
{
  readTxt("data.txt");
  readTxt2("data.txt");
  readTxt3("data.txt");
  return 0;
}