C++文件的读取和写入

1、C++对txt文件的读，ios::in

#include<iostream>
#include<fstream>
using namespace std;int main()
{ifstream ifs;ifs.open("test.txt",ios::in);if(!ifs.is_open()){cout<<"打开文件失败！"<<endl;}char buff[1024] ={0};while(ifs>>buff){cout<<buff<<endl;}return 0;
}

2、c++对txt文件的写文件，ios::out

#include<iostream>
#include<fstream>
using namespace std;
int main()
{ofstream ofs;ofs.open("test1.txt",ios::out);ofs<<"岗位：LISI"<<endl<<"年龄：19"<<endl<<"xingbie:男"<<endl;ofs.close();return 0;
}

3、c++对txt文件的写文件，追加到目前文件的最后，ios::app

#include<iostream>
#include<fstream>
using namespace std;
int main()
{ofstream ofs;ofs.open("test1.txt",ios::app);ofs<<"岗位：LISI"<<endl<<"年龄：19"<<endl<<"xingbie:男"<<endl;ofs.close();return 0;
}

4、c++读取二进制文件，ios::in|ios::binary

#include<iostream>
using namespace std;
#include<fstream>
class CStudent
{public:char name[100];int age;
};int main()
{CStudent cs;ifstream infile("student.dat",ios::in|ios::binary);if(!infile)cout<<"error"<<endl;while(infile.read((char*)&cs,sizeof(cs))){int readBytes=infile.gcount();cout<<cs.name<<cs.age<<endl;}infile.close();return 0;
}

5、c++写二进制文件，ios::out|ios::binary

#include<iostream>
#include<fstream>
using namespace std;class CStudent
{public:char name[100];int age;
};int main()
{CStudent cs;ofstream outfile("student.dat",ios::out|ios::binary);while(cin>>cs.name>>cs.age)outfile.write((char*)&cs,sizeof(cs));outfile.close();return 0;
}