=====getline=====
Syntax:

<code>
    #include <string>
    istream& getline( istream& is, string& s, char delimiter = '\n' );
</code>

The C++ string class defines the global function getline() to read strings from
an I/O stream. The getline() function, which is not part of the string class,
reads a line from is and stores it into s. If a character delimiter is
specified, then getline() will use delimiter to decide when to stop reading
data.

For example, the following code reads a line of text from stdin and displays it
to stdout:

<code>
   string s;
   getline( cin, s );
   cout << "You entered " << s << endl;
</code>

After getting a line of data in a string, you may find that [[io/sstream/|stringstreams]] are
useful in extracting data from that string. For example, the following code
reads numbers from standard input, ignoring any "commented" lines that begin
with double slashes:

<code>
    // expects either space-delimited numbers or lines that start with
    // two forward slashes (//)
    string s;
    while( getline(cin,s) ) {
      if( s.size() >= 2 && s[0] == '/' && s[1] == '/' ) {
        cout << "  ignoring comment: " << s << endl;
      } else {
        istringstream ss(s);
        double d;
        while( ss >> d ) {
          cout << "  got a number: " << d << endl;
        }
      }
    }
</code>

When run with a user supplying input, the above code might produce this output:

<code terminal>
    // test
      ignoring comment: // test
    23.3 -1 3.14159
      got a number: 23.3
      got a number: -1
      got a number: 3.14159
    // next batch
      ignoring comment: // next batch
    1 2 3 4 5
      got a number: 1
      got a number: 2
      got a number: 3
      got a number: 4
      got a number: 5
    50
      got a number: 50
</code>

Related Topics: [[io/get]], [[io/getline]], [[io/sstream/|stringstream]]