Question

c++打开文件和关闭文件的函数及用法

Answer 1

c:
fopen,fclose
c++:
输入文件：
fstream myfile;
myfile.open("test.txt",ios::out|ios::trunc);
cin>>myfile;
myfile.close;
输出文件：
char data[8];
ifstream myfile;
myfile.open("test.txt");
myfile>>data;

以上都没判断文件是否存在

Answer 2

例如，打开D盘下的a.txt文件：
FILE *fp = fopen("d:\\a.txt", "w");//打开文件
……
fclose(fp);//关闭文件

Answer 3

#include <iostream>
#include <fstream>
using namespace std;

int main()
{
string str;
int i;
i=0;
ofstream outfile("test.data",ios::out);
if(!outfile)
{
cerr<<"open error!"<<endl;
}else{
outfile<<"this is test content!";

}
outfile.close();

ifstream ifile("test.data",ios::in);
if(!ifile)
{
cerr<<"read error!"<<endl;
}else{
//cout<<"Yes"<<endl;
ifile>>str;
}
ifile.close();
cout<<str<<endl;
}