How to extract the elements of std::string c

Question

I have a std::sting like that:

std::string Str = "PARAM1;PARAM2;PARAM3;PARAM4"

and I need to extract each parameters like:

char* param1 = explodStr[1] //return PARAM1 ...

I'm not familiar with std::string,

thank you

If you're not familiar with a subject, you should **learn** the subject. StackOverflow isn't a tutorial site. You can come back *after* you've made an effort to learn the subject and hit a specific obstacle. — Kerrek SB, Feb 07 '13 at 13:55
@KerrekSB: When SO has comment templates/presets, this should be one of them. — Lightness Races in Orbit, Feb 07 '13 at 14:10

score 0 · Answer 1 · answered Feb 07 '13 at 13:58

I often use this function for this type of task. It acts like PHP's explode:

//------------------------------------------------------------------------------
// Name: explode
// Desc: Returns an array of strings, each of which is a substring of <s>
//       formed by splitting it on boundaries formed by the string <delimiter>.
//       (similar to PHP's explode)
//------------------------------------------------------------------------------
inline std::vector<std::string> explode(const std::string &delimeter, const std::string &s, int limit) {
    std::vector<std::string> results;

    if(!delimeter.empty()) {    

        std::string::size_type start = 0;
        std::string::size_type end   = s.find(delimeter, start);

        if(limit <= 0) {
            while(end != std::string::npos) {           
                results.push_back(s.substr(start, end - start));
                start = end + delimeter.size();
                end = s.find(delimeter, start);

                if(start == s.size() && end == std::string::npos) {
                    results.push_back(std::string());   
                }
            }
        } else if(limit > 0) {
            while(--limit > 0 && end != std::string::npos) {
                results.push_back(s.substr(start, end - start));
                start = end + delimeter.size();
                end = s.find(delimeter, start);

                if(start == s.size() && end == std::string::npos) {
                    results.push_back(std::string());   
                }
            }
        }

        if(start != s.size()) {
            results.push_back(s.substr(start)); 
        }

        while(limit++ < 0 && !results.empty()) {
            results.pop_back();
        }
    }

    return results;
}

Or with no limit:

//------------------------------------------------------------------------------
// Name: explode
// Desc: Returns an array of strings, each of which is a substring of <s>
//       formed by splitting it on boundaries formed by the string <delimiter>.
//       (similar to PHP's explode)
//------------------------------------------------------------------------------
inline std::vector<std::string> explode(const std::string &delimeter, const std::string &s) {
    return explode(delimeter, s, 0);
}

Usage looks like this:

std::vector<std::string> x = explode(",", "THIS,IS,A,TEST");

How to extract the elements of std::string c

1 Answers1