实验七

11-3

#include<iostream>
#include<fstream>
using namespace std;
int main() {
    ofstream file("test1.txt");
    file<< "已成功写入文件！";
    file.close();
    return 0;
}

11-4

#include<fstream>
#include<iostream>
using namespace std;
int main(){
    char ch;
    ifstream file1("test.txt");
    while(file1.get(ch))
    cout<<ch;
    file1.close();
}

11-7

#include <iostream>
using namespace ::std;
int main()
{
ios_base::fmtflags original_flags = cout.flags();
cout<< 812<<'|';
cout.setf(ios_base::left,ios_base::adjustfield);
cout.width(10);
cout<<813<<815<<'\n';
cout.unsetf(ios_base::adjustfield);
cout.precision(2);
cout.setf(ios_base::uppercase|ios_base::scientific);
cout << 831.0 ;
cout.flags(original_flags); 
}