Re: converting a string to an array of words

From:
"Jim Langston" <tazmaster@rocketmail.com>
Newsgroups:
comp.lang.c++
Date:
Thu, 19 Apr 2007 09:50:53 -0700
Message-ID:
<d6NVh.40$lq2.0@newsfe04.lga>
"Frederik Van Bogaert" <frederik.vanbogaert@student.kuleuven.be> wrote in
message news:f0868e$m52$1@ikaria.belnet.be...

Jim Langston wrote:

"Frederik Van Bogaert" <frederik.vanbogaert@student.kuleuven.be> wrote in
message news:f084mn$lbd$1@ikaria.belnet.be...

Hi! I've taken my first steps into the world of c++ by trying to write a
text adventure game. Things are proceeding fine, but there's some code
in there that isn't very well coded. More specifically, I use the
following code:

...
string word [4];
size_t pos = action.find(" ");
word[0] = action.substr (0,pos);
if (pos < action.size() - 2)
{
word[1] = action.substr(pos + 1);
}
string word1 [2];

for (int i=1;i<3;i++)
{
pos = word[i].find(" ");
if (pos == string::npos) goto skippy;
word1[i-1] = word[i].substr (0,pos);
if (pos < word[i].size() - 2)
{
word[i+1] = word[i].substr(pos + 1);
}
word[i] = word1[i-1];
}

skippy:
...

To convert a string called 'action' into the array word[4]. Is there a
way to do this more efficiently?
Thanks


Use. std::stringstream. stringstream will read using >> like std::cin,
stopping on spaces.

Output of following program is:

look
at
the
clock
on
the
wall

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

// typedef is not required, just makes it a little eaiser.
typedef std::vector<std::string> WordVec;

int main()
{
    std::string action = "look at the clock on the wall";

    WordVec Words;
    // Following declares a stringstream Parse and initializes it to the
contents of action
    std::stringstream Parse( action );

    // Now we read each word out one by one til there's no more and stuff
them into our vector
    std::string word;
    while ( Parse >> word )
        Words.push_back( word );

    // At this point each word is in the vector.

    for ( WordVec::iterator it = Words.begin(); it != Words.end(); ++it )
        std::cout << (*it) << "\n";

    std::string wait;
    std::getline( std::cin, wait );
}


Thanks! That's exactly what I was looking for :-)

PS: Is there some reason you're using "std::" all the time instead of
specifying "using namespace std;" in the beginning of the file as I've
been told to do?


Because I feel that "using namespace std;" defeats the purpose of namespaces
to begin win. Check out the FAQ:

http://www.parashift.com/c++-faq-lite/coding-standards.html#faq-27.5

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