Splitting a string by a character

Question

I know this is a quite easy problem but I just want to solve it for myself once and for all

I would simply like to split a string into an array using a character as

Answer 1

I inherently dislike stringstream, although I'm not sure why. Today, I wrote this function to allow splitting a std::string by any arbitrary character or string into a vector. I know this question is old, but I wanted to share an alternative way of splitting std::string.

This code omits the part of the string you split by from the results altogether, although it could be easily modified to include them.

#include 
#include 

void split(std::string str, std::string splitBy, std::vector& tokens)
{
    /* Store the original string in the array, so we can loop the rest
     * of the algorithm. */
    tokens.push_back(str);

    // Store the split index in a 'size_t' (unsigned integer) type.
    size_t splitAt;
    // Store the size of what we're splicing out.
    size_t splitLen = splitBy.size();
    // Create a string for temporarily storing the fragment we're processing.
    std::string frag;
    // Loop infinitely - break is internal.
    while(true)
    {
        /* Store the last string in the vector, which is the only logical
         * candidate for processing. */
        frag = tokens.back();
        /* The index where the split is. */
        splitAt = frag.find(splitBy);
        // If we didn't find a new split point...
        if(splitAt == string::npos)
        {
            // Break the loop and (implicitly) return.
            break;
        }
        /* Put everything from the left side of the split where the string
         * being processed used to be. */
        tokens.back() = frag.substr(0, splitAt);
        /* Push everything from the right side of the split to the next empty
         * index in the vector. */
        tokens.push_back(frag.substr(splitAt+splitLen, frag.size()-(splitAt+splitLen)));
    }
}

To use, just call like so...

std::string foo = "This is some string I want to split by spaces.";
std::vector results;
split(foo, " ", results);

You can now access all the results in the vector at will. Simple as that - no stringstream, no third party libraries, no dropping back to C!