c++使用getline和ifstream读取文件

假设有一个叫 data.txt 的文件, 它包含以下内容:

Fry: One Jillion dollars.
 [Everyone gasps.]
 Auctioneer: Sir, that's not a number.
 数据读取， 测试 。

以下就是基于 data.txt 的数据读取操作:

#include<iostream>
#include<fstream>
#include<string>
using namespace std;
 
 //输出空行
 void OutPutAnEmptyLine(){
 	cout<<'/n'<<endl;
 }

//读取方式：逐词读取Word by Word，词之间用空格划分
void ReadDataFromFileWBW(){
	ifstram fin("data.txt");
	string s;
	while(fin>>s){
		cout<<"Read From file: "<<s<<endl;
	}
}

//读取方式:逐行读取Line by Line, 将行读入字符数组, 行之间用回车换行区分
void ReadDataFromfileLBLIntoCharArray(){
	ifstream fin("data.txt");
	const int LINE_LENGTH=100;
	char str[LINE_LENGTH];
	while(fin.getline(str,LINE_LENGTH)){
		cout<<"Read From Data: "<<str<<endl;
		}
}

// 读取方式: 逐行读取, 将行读入字符串, 行之间用回车换行区分
void ReadDataFromFileLBLIntoString()
 {
      ifstream fin( " data.txt " );  
      string s;  
      while ( getline(fin,s) )
      {    
          cout << " Read from file: " << s << endl;
      }
 }

// 带错误检测的读取方式
void ReadDataWithErrChecking()
 {
      string filename = "dataFUNNY .txt " ;  
      ifstream fin( filename.c_str());  
      if ( ! fin )
      {   
          cout << " Error opening " << filename << " for input " << endl;   
          exit( - 1 );  
      }
 }

int main()
{
    ReadDataFromFileWBW(); //逐词读入字符串 
    OutPutAnEmptyLine(); //输出空行

    ReadDataFromFileLBLIntoCharArray(); //逐词读入字符数组
    OutPutAnEmptyLine(); //输出空行

    ReadDataFromFileLBLIntoString(); //逐词读入字符串
    OutPutAnEmptyLine(); //输出空行

    ReadDataWithErrChecking(); //带检测的读取
    return 0;
}

输出结果为:
Read from file: Fry:
Read from file: One
Read from file: Jillion
Read from file: dollars.
Read from file: [Everyone
Read from file: gasps.]
Read from file: Auctioneer:
Read from file: Sir,
Read from file: that’s
Read from file: not
Read from file: a
Read from file: number.
Read from file: 数据读取，
Read from file: 测试
Read from file: 。

Read from file: Fry: One Jillion dollars.
Read from file: [Everyone gasps.]
Read from file: Auctioneer: Sir, that’s not a number.
Read from file: 数据读取，测试。

Error opening dataFUNNY.txt for input
Press any key to continue

c++使用getline和ifstream读取文件

猜你喜欢