Which of the following is correct for opening a file and attaching it to a file named File.txt? Assume proper file inclusion and proper using directives.

Question

a) ```
open(outStream, “File.txt”, ios::app)
```

b) ```
ifstream inStream;
inStream.open(“File.txt”);
```

c) ```
ifstream inStream(“File.txt”);
```

d) ```
ofstream inStream;
onStream.open(“File.txt”, ios::app);
```

e) ```
ifstream inStream(“File.txt”, ios::app);
```

Answer 1

All but a) are correct.

Part a) mistakes the open member function for a standalone function. Part b) declares the stream and separately calls the open member function for input. Part c) is the abbreviated form to open File.txt. Part d) is the detailed open for append. Part e) is the abbreviated form of d).