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Inserting data
somewhere in a sequential file would require that the entire file be rewritten.
It is possible,
however, to add data to the end of a file without rewriting the file.
Adding data to the end of an existing file is called appending.
fout.open("filename.dat", ios::app)
//open file for appending
//add names and ages
to an existing file
#include <iostream.h>
#include <fstream.h> |
If the file you open for appending does not exist, the
operating system creates one just as if you had opened it using ios::out
mode. |
int main(void)
{
apstring name, dummy;
int number, i, age;
ofstream fout;
cout<<"How
many names do you want to add?";
cin>>number;
getline(cin,dummy);
fout.open("name_age.dat",ios::app); //
open file for appending
assert (!fout.fail( ));
for(i=1; i<=number;
i++)
{
cout<<"Enter the
name: ";
getline(cin,name);
cout<<"Enter
age: ";
cin>>age;
getline(cin,age);
fout<<name<<endl; //send to
file
fout<<age<<endl;
}
fout.close( ); //close
file
assert(!fout.fail( ));
return 0;
}
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