what is the best way to split string ? (c++)

Question

I have a string and I want to split it every time the char ',' appears. I want to save the result in a vector of pointers to string. What is the best way to do this?

Answer 1

boost::algorithm::split

Or write your own. This algorithm is pretty easy to write in terms of std::find.

Answer 2

"i want to split it every time that the char ',' ..."

Use std::getline and specify the delimiter (last argument) to be ','.

"I want to save the result in a vector of pointers to string"

You want to avoid using vector of pointers, believe me. Use std::vector<std::string> instead:

std::istringstream is(",,,my,,weird,string");

std::vector<std::string> tokens;
std::string token;
while (std::getline(is, token, ',')) {
    if (!token.empty())
        tokens.push_back(token);
}

for (int i = 0; i < tokens.size(); ++i)
    std::cout << tokens[i] << " ";

outputs my weird string. Just don't forget to #include <sstream>.

Answer 3

I've used strtok to tokenize string, but this has a few drawbacks:

• This is part of cstring and it's used for C-style strings, and not std::string objects.
• It's kind of clumsy in terms of having to call it several times changing the parameter after the first time.

It's not ideal if you have boost available but it should work for all implementations of C++.