Reputation: 14011

How to split the strings in vc++?

I have a string "stack+ovrflow*newyork;" i have to split this stack,overflow,newyork

any idea??

Upvotes: 1

Answers (6)

luowen

Reputation: 21

There is another way to split a string using c/c++ :

First define a function to split a string:

//pointers of the substrings, assume the number of fields will not be over 5
char *fields[5];   
//str: the string to splitted
//splitter: the split charactor
//return the real number of fields or 0 if any error exits
int split(char* str, char *splitter)
{
    if(NULL == str) 
    {
        return 0;
    }

    int cnt;
    fields[0] = str;
    for(cnt = 1; (fields[cnt] = strstr(fields[cnt - 1], splitter)) != NULL && 
            cnt < 5; cnt++)
    {
        *fields[cnt] = '\0';
        ++fields[cnt];
    }
    return cnt;
}

then you can use this function to split string as following:

char* str = "stack+ovrflow*newyork;"
split(str, "+");
printf("%s\n", fields[0]); //print "stack"
split(fields[1], "*");
printf("%s\n", fields[0]); //print "ovrflow"
split(fields[1], ";");
printf("%s\n", fields[0]); //print "newyork"

this way will be more efficient and reusable

Upvotes: 2

Doug T.

Reputation: 65609

First and foremost if available, I would always use boost::tokenizer for this kind of task (see and upvote the great answers below)

Without access to boost, you have a couple of options:

You can use C++ std::strings and parse them using a stringstream and getline (safest way)

std::string str = "stack+overflow*newyork;";
std::istringstream stream(str);
std::string tok1;
std::string tok2;
std::string tok3;

std::getline(stream, tok1, '+');
std::getline(stream, tok2, '*');
std::getline(stream, tok3, ';');

std::cout << tok1 << "," << tok2 << "," << tok3 << std::endl

Or you can use one of the strtok family of functions (see Naveen's answer for the unicode agnostic version; see xtofls comments below for warnings about thread safety), if you are comfortable with char pointers

char str[30]; 
strncpy(str, "stack+overflow*newyork;", 30);

// point to the delimeters
char* result1 = strtok(str, "+");
char* result2 = strtok(str, "*");
char* result3 = strtok(str, ";");

// replace these with commas
if (result1 != NULL)
{
   *result1 = ',';
}
if (result2 != NULL)
{
   *result2 = ',';
}

// output the result
printf(str);

Upvotes: 11

Gustavo Muenz

Reputation: 9552

Boost tokenizer

Simple like this:

#include <boost/tokenizer.hpp>
#include <vector>
#include <string>
std::string stringToTokenize= "stack+ovrflow*newyork;";
boost::char_separator<char> sep("+*;");
boost::tokenizer< boost::char_separator<char> > tok(stringToTokenize, sep);
std::vector<std::string> vectorWithTokenizedStrings;
vectorWithTokenizedStrings.assign(tok.begin(), tok.end());

Now vectorWithTokenizedStrings has the tokens you are looking for. Notice the boost::char_separator variable. It holds the separators between the tokens.

Upvotes: 6