converting a std::string to an array of c strings

Question

I'm trying to find a way to convert a string to array of c strings. So for example my string would be:

std::string s = "This is a string."

and then I would like the output to be something like this:

array[0] = This
array[1] = is
array[2] = a
array[3] = string.
array[4] = NULL

http://stackoverflow.com/questions/236129/splitting-a-string-in-c — Pavel Dudka, Feb 12 '13 at 01:06
So you have an array of `std::string`s? Like `std::string strings[5];`? — Mark Garcia, Feb 12 '13 at 01:06
You're splitting a string on whitespaces, not converting to a character array. That first link works, or you can search 'splitting a string c++' to find what you want. — evanmcdonnal, Feb 12 '13 at 01:07
Removed the C tag, as the question is meaningless in C. In C, a string is an array of characters, so there's no conversion to be done. — William Pursell, Feb 12 '13 at 01:08
I guess what I meant to say was I'd like to convert the std::string into an array of c strings. — Peter T., Feb 12 '13 at 01:18

score 4 · Answer 1 · edited May 23 '17 at 11:52

4

You are trying to split string into strings. Try:

 #include <sstream>
 #include <vector>
 #include <iostream>
 #include <string>

 std::string s = "This is a string.";

  std::vector<std::string> array;
  std::stringstream ss(s);
  std::string tmp;
  while(std::getline(ss, tmp, ' '))
  {
    array.push_back(tmp);
  }

  for(auto it = array.begin(); it != array.end(); ++it)
  {
    std::cout << (*it) << std:: endl;
  }

Or see this split

edited May 23 '17 at 11:52

Community

1
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answered Feb 12 '13 at 01:21

billz

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I tried using your example but I get this "error: variable 'std::stringstream ss' has initializer but incomplete type" – Peter T. Feb 12 '13 at 01:41
you need to include necessary headers, see my updated answer – billz Feb 12 '13 at 01:42
Ahh, I had the other 3 I was just missing the sstream. Thanks a lot, this has been a big help. – Peter T. Feb 12 '13 at 01:47

score 1 · Answer 2 · edited May 23 '17 at 12:03

Split your string into multiple strings based on a delimiter using the Boost library function 'split' like this:

#include <boost/algorithm/string.hpp>
std::vector<std::string> strs;
boost::split(strs, "string to split", boost::is_any_of(" "));

And then iterate over the strs vector.

This approach allows you to specify as many delimiters as you like.

See here for more: http://www.boost.org/doc/libs/1_48_0/doc/html/string_algo/usage.html#id3115768

And there is a plethora of approaches here: Split a string in C++?

score -2 · Answer 3 · answered Feb 12 '13 at 01:19

On your example.

The array is not an array of characters, it is an array of strings.

Well, actually, a string is an array of characters.

//Let's say:
string s = "This is a string.";
//Therefore:
s[0] = T
s[1] = h
s[2] = i
s[3] = s

But based on your example,

I think you want to Split the text. (with SPACE as delimeter).

You can use the Split function of the String.

string s = "This is a string.";
string[] words = s.Split(' ');
//Therefore:
words[0] = This
words[1] = is
words[2] = a
words[3] = string.

You're going to have to divulge which **C++** standard dictates the `Split()` member of `std::string`. This isn't Java. — WhozCraig, Feb 12 '13 at 01:24

converting a std::string to an array of c strings

3 Answers3