cout<<字符数组 getline（流，string，delimit character） 遇到的问题

#include <iostream>#include <string>using namespace std;#include <fstream>void main(){cout<<"please input two line string : "<<endl;/*string str=NULL;//--used to store a string //============must be initialize. when define, initialize it is a good habit//-------notice that the second parameter is string object instead of c-string getline(cin, str,' ');//----------getline is global function unlike the member of stream classcout<<"str :"<<str;getline(cin,str);//---------the pointer of the output stream is moved cout<<"str :"<<str<<endl;*//*char* c=NULL;//======================wrong : the memory cann't written. c should a array of character============cin.getline(c, 12);cout<<"c :"<<c;*//*char c[25];cin.getline(c, 12);//---notice : the function needn't concern you about the istream object, for it is precise as you see.//------------------and the first parameter is c-string instead of string object. please remember it .cout<<"c :"<<c<<endl;*///========================= test : getline from a txt file=========================== string str;ifstream infile;//infile.open("data.txt",ios::out);//==================所有的读取文件导致的错误maybe都源于ios：：out infile.open("data.txt",ios::in);if (!infile)cerr<<"open the file fail."<<endl;if (!infile.is_open())cerr<<"open the file fail."<<endl;//=====================this a logic wrong. the c is output unlimited/*while(!infile.eof()){infile.getline(c,12);cout<<"c :"<<endl;}*///------------it is good way, to me, to getline from a istream object------------/*while(!infile.eof()){getline(infile,str);cout<<"getline(infile,str) : "<<str<<endl;}*/ //-----------/* char c[25];infile.getline(c,6);cout<<"c :"<<c<<endl;//=============注意：输出是字符串而不是c[0]*///=================一个无限循环，死循环,总是输出无数的：“c :”===========/*char c[25];while(!infile.eof()){infile.getline(c,6);cout<<"c :"<<c<<endl;//=============注意：输出是字符串而不是c[0]}*//**/int i=25;char c[25];char ch;while(!infile.eof()&& i){////////////////////////////////////////////////////////////////////////////=======输出很奇怪=======cout<<"infile.eof() = "<<infile.eof()<<endl; //======输出总是 0cout<<"infile.eofbit = "<<infile.eofbit<<endl;//======输出总是 1cout<<"infile.good ="<<infile.good()<<endl;infile.getline(c,6);ch=infile.get();cout<<"infile.get(ch) :"<<ch<<endl;cout<<"the postition @ : "<<infile.tellg()<<endl;//========总是输出 -1cout<<"c :"<<c<<endl;//=============注意：输出是字符串，而不是c[0]i--;} /************************************************************************//* cout<<数组首地址，将输出整个数组？ 错。cout<< 要看类型，智能输出。类型为int或其他，cout<<首地址，没有什么特殊就是一个地址。但是当输出字符数组时会输出整个字符串，cout会把整个字符串输出来，输出来'/1'——它是一个笑脸符号。 int a[]={1,2,3,4};char b[]={'a','b','c','d'};cout<<"cout<<a : "<<a <<endl;//==========输出为0012FAE4==========这是一个地址。cout<<"cout<<b :"<<b <<endl;//=======abcd笑脸符号====因为C语言中自动把字符数组和字符串等价。//你需要定义数组足够大，因为系统要添加一个‘/0’字符串结束符*//************************************************************************//************************************************************************//* cout<<数组首地址，将输出整个数组？ int a[4]={1,2,3,4};char b[4]={'a','b','c','d'};cout<<"cout<<a : "<<a <<endl;//==========输出为0012FAE4cout<<"cout<<b :"<<b+1 <<endl;//======= bcd笑脸符号 //====从第二个字符到数组末尾cout<<"'//0' :"<<'/0'<<endl;cout<<"'//1' :"<<'/1'<<endl; *//************************************************************************//************************************************************************//* cout<<数组首地址，将输出整个数组？ int a[8]={1,2,3,4};char b[8]={'a','b','c','d'};cout<<"cout<<(*(a+7)) : "<<(*(a+7)) <<endl;//==========输出0 ======系统默认初始化为 0cout<<"cout<<b :"<<b+1 <<endl;//======= bcd //====从第二个字符到数组末尾，并没有输出笑脸.系统子自动给字符串添加一个‘/0’=====不是一个，是空余空间都填充‘/0’cout<<"cout<<b :"<<b+7 <<endl; //=======输出为空cout<<"cout<<b :"<<*(b+7) <<endl; //=======输出为 '/0'——像小乌龟字符cout<<"cout<<b :"<<b+8 <<endl; //====输出一个笑脸cout<<"'//0' :"<<'/0'<<endl;cout<<"'//1' :"<<'/1'<<endl; *//************************************************************************//************************************************************************//* 不良习惯1. 定义数组和string 没有赋值，没有初始化。 ====》变量一定义就要初始化。2. 文件没有关闭。 ====》文件一打开，就要写关闭。*//************************************************************************/infile.close();infile.clear();}/************************************************************************//* output resultwhen I input one line : iamlijiangtao is a fresh man.console result output : str :iamlijiangtaostr :is a fresh man.c: //================there is nothing output.because all of the cin object is output and store in str objectpress any key to continue. explanation:the getline(istream object, string ,delimiting character) function is global function, and it means that : extract a string from istream object, if encounter a delimiting character, stop and desert it. *//************************************************************************/