getlin()的施用

getlin()的使用

假设有一个叫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";
}

//读取方式:?逐词读取,?词之间用空格区分
//read?data?from?the?file,?Word?By?Word
//when?used?in?this?manner,?we'll?get?space-delimited?bits?of?text?from?the?file
//but?all?of?the?whitespace?that?separated?words?(including?newlines)?was?lost.?
void?ReadDataFromFileWBW()
{
????ifstream?fin("data.txt");??
????string?s;??
????while(?fin?>>?s?)?
????{????
????????cout?<<?"Read?from?file:?"?<<?s?<<?endl;??
????}
}

//读取方式:?逐行读取,?将行读入字符数组,?行之间用回车换行区分
//If?we?were?interested?in?preserving?whitespace,?
//we?could?read?the?file?in?Line-By-Line?using?the?I/O?getline()?function.
void?ReadDataFromFileLBLIntoCharArray()
{
????ifstream?fin("data.txt");?
????const?int?LINE_LENGTH?=?100;?
????char?str[LINE_LENGTH];??
????while(?fin.getline(str,LINE_LENGTH)?)
????{????
????????cout?<<?"Read?from?file:?"?<<?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
//If?you?want?to?avoid?reading?into?character?arrays,?
//you?can?use?the?C++?string?getline()?function?to?read?lines?into?strings
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
//Simply?evaluating?an?I/O?object?in?a?boolean?context?will?return?false?
//if?any?errors?have?occurred
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 。

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
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