Re: STL vector - which style of for() loop?

From:
Gerry Hickman <gerry666uk@newsgroup.nospam>
Newsgroups:
microsoft.public.vc.language
Date:
Sun, 22 Jul 2007 14:39:14 +0100
Message-ID:
<#G2V0WGzHHA.1168@TK2MSFTNGP02.phx.gbl>
Hi Jeff,

When I tried to run your version it didn't like the "argument list" for
ostream_iterator(cout), I then added this line to the header file

typedef ostream_iterator <string, char, char_traits <char> > OstreamIt;

I then changed the code slightly to

copy( TheStrings.begin()
     , TheStrings.end()
     , OstreamIt(cout, " ") );

It now works, but it concatenates the strings, instead of putting them
on new lines. I don't understand:

A) the typedef in the header and why it works, or even if it's correct
B) The comma operator where it says OstreamIt(cout, " ")

I like the look of your version, but need more info on how to code it
properly and how to control the formatting.

Jeff Flinn wrote:

See inline below:

Gerry Hickman wrote:

Hi,

I have this code below, and would like to know which for() loop style
is best - the second one seems a bit of a mouthful!

* Beware line wrap *

int _tmain(int argc, _TCHAR* argv[])
{

    // Call a function that populates strings

    vector< string > TheStrings;

    TheStrings = returnStrings();

    for(unsigned i = 0; i < TheStrings.size(); i++) {
        cout << TheStrings[i] << endl;
    }

    for(vector<string>::iterator myIterator = TheStrings.begin();
myIterator != TheStrings.end(); myIterator++)
    {
        cout << *myIterator << endl;
    }


    std::copy( TheStrings.begin()
                 , TheStrings.end()
                 , std::ostream_iterator(cout) );

    return 0;
}

vector< string > returnStrings()
{
    // From Google Groups, demo of how to return a vector from a func
    vector< string > Strings;

    Strings.push_back( "hello" );
    Strings.push_back( "hello1" );
    Strings.push_back( "hello2" );

    return Strings; // Original author didn't have this?

}


Jeff F


--
Gerry Hickman (London UK)

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