Split a string

Question

How do I split a string by " - ". Note it is space-dash-space. Example this string: "something - some-thing so - me-thing" should give me an array containing "something", "some-thing so", "me-thing". Any elegant solution will be appreciated. Thanks.

Answer 1

How do I split a string by " - ". Note it is space-dash-space. Example this string: "something - some-thing so - me-thing" should give me an array containing "something", "some-thing so", "me-thing". Any elegant solution will be appreciated. Thanks.

It really depends on what kind of string you're using.
std::string, C-style string, MFC CString, System::String,
etc.

For a std::string you can use the string::find and
string::substr member functions.

Something approximately like this:

#include "stdafx.h"
#include <string>
#include <vector>
#include <iostream>

using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
  const string str("something - some-thing so - me-thing");
  string work(str);
  string pattern(" - ");
  string subs;
  vector<string> vs;

  string::size_type si;
  while((si = work.find(pattern)) != string::npos)
    {
    subs = work.substr(0, si);
    vs.push_back(subs);
    work.erase(0, si + 3);
    }
  vs.push_back(work);

  cout << str << endl;
  for(string::size_type n=0; n<vs.size(); ++n)
    {
    cout << vs[n] << endl;
    }

  return 0;
}

E&OE

- Wayne

Answer 2

regex is easier to write and to generalize (what if you want dashes surrounded by arbitrary amounts of whitespace to be your field splitters?):

C:\Temp>type meow.cpp
#include <iostream>
#include <ostream>
#include <regex>
#include <string>
#include <vector>
using namespace std;

int main() {
    const string s("something - some-thing so - me-thing");
    const regex r(" - ");

    const vector<string> v(sregex_token_iterator(s.begin(), s.end(), r, -1), sregex_token_iterator());

    for (auto i = v.begin(), end = v.end(); i != end; ++i) {
        cout << "\"" << *i << "\"" << endl;
    }
}

C:\Temp>cl /EHsc /nologo /W4 /MTd meow.cpp
meow.cpp

C:\Temp>meow
"something"
"some-thing so"
"me-thing"