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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

Frederik Van Bogaert wrote:
> [..]
>
> To convert a string called 'action' into the array word[4]. Is there a
> way to do this more efficiently?

Not sure about efficiency. But elegance is relatively easy to come by.
All you need to do is take your string, construct a stringstream out of
it and then read all the words from it until end-of-file.

V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask

"Frederik Van Bogaert" <> wrote in
message news:f084mn$lbd$...
> 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 );
}

Jim Langston wrote:
> "Frederik Van Bogaert" <> wrote in
> message news:f084mn$lbd$...
>> 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?

Jim Langston wrote:
> [..]
> // 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 );

Replace the three lines above with this:

std::copy(std::istream_iterator<std::string>(Parse ),
std::istream_iterator<std::string>(),
std::back_inserter(Words));

>
> // At this point each word is in the vector.
>
> for ( WordVec::iterator it = Words.begin(); it != Words.end();
> ++it ) std::cout << (*it) << "\n";

Replace the loop with this:

std::copy(Words.begin(), Words.end(),
std:stream_iterator<std::string>(std::cout, "\n"));

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

And you get an even more radical standard-library based program!

V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask

"Frederik Van Bogaert" <> wrote in
message news:f0868e$m52$...
> Jim Langston wrote:
>> "Frederik Van Bogaert" <> wrote in
>> message news:f084mn$lbd$...
>>> 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-lit....html#faq-27.5