C++ read string with spaces

问题

I have file like this:

59 137 New York
137 362 Syracuse
216 131 New Jersey
...
..
.

and I would like to read it to a structure: X - Y - name of a city

  char city[100];
  int x , y;
  f.open("map.txt");
  f >> x >> y >> city;
  while (!f.fail()) {
    f >> x >> y >> city;
  }
  f.close();

Problem is, that city reads only until next space, so from New York it reads only New. How should I read whole rest of a line, in some easy and smart way ?

回答1:

The format of your file seems to imply that the name of the city ends at the end of a line, not a space.

You can read that form using getline

  char city[100];
  int x , y;
  f.open("map.txt");
  while ( f ) {
      f >> x >> y;         
      f.getline(city, 100); 
  }
  f.close();

回答2:

You can do something like this:

  f.open("map.txt");
  string city;
  int x , y;
  f >> x >> y;
  getline(f,city);

  while (!f.fail()) {
  f >> x >> y;
  getline(f,city);
  }
  f.close();

回答3:

Use getline(f, city) for city. So, you have f >> x >> y; getline(f, city);

回答4:

This code reads spaces and handles end of file correctly. None of the other answers do this I think

while ((f >> x >> y).getline(city, 100))
{
}

See this for more information on how to correctly test for end of file.

Of course you should be doing things the easy way using std::string as others have said.

来源：https://stackoverflow.com/questions/16002833/c-read-string-with-spaces