Streams

Reading and Writing Text Files

To access a disk file, you need to open a file variable.
- type ifstream for input
```
ifstream input_data;
```
- type ofstream for output
- type fstream for both input and output
To read anything from a file, you need to open it.
```
input_data.open("input.dat");
```
To read from the file, use the name of the ifstream variable in place of cin.
```
int n;
double x;
input_data >> n >> x;
```

You read in strings in the usual way.

string s;
input_data >> s; /* read a word */
getline(input_data, s); /* read a line */