printing list elements

[sam]

Hi,

I use "list" data container from STL.
I m wondering how to print out all items from a list thru its iterator?
I currently use two "for loop" for each list:

list<HashMap>::iterator l_iter;
HashMap::iterator m_iter;
for (l_iter=macro_list.begin(); l_iter!=macro_list.end(); l_iter++) {
for (m_iter=l_iter->begin(); m_iter!=l_iter->end(); m_iter++) {
cout << m_iter->first << endl;
}
}
}

Is there any other better way can handle this treversal better?

Thanks
Sam

 

[Thomas Maier-Komor]

Hi,

I use "list" data container from STL.
I m wondering how to print out all items from a list thru its iterator?
I currently use two "for loop" for each list:

list<HashMap>::iterator l_iter;
HashMap::iterator m_iter;
for (l_iter=macro_list.begin(); l_iter!=macro_list.end(); l_iter++) {
for (m_iter=l_iter->begin(); m_iter!=l_iter->end(); m_iter++) {
cout << m_iter->first << endl;
}
}
}

Is there any other better way can handle this treversal better?

Thanks
Sam

what do you mean by "better"?

for enhanced readability and performance one might use for_each. But
this requires to write a Functor - i.e. it is more complicated to
understand and requires more lines of code...

Tom

 

[m.a.stijnman]

Hi,

I use "list" data container from STL.
I m wondering how to print out all items from a list thru its iterator?
I currently use two "for loop" for each list:

list<HashMap>::iterator l_iter;
HashMap::iterator m_iter;
for (l_iter=macro_list.begin(); l_iter!=macro_list.end(); l_iter++) {
for (m_iter=l_iter->begin(); m_iter!=l_iter->end(); m_iter++) {
cout << m_iter->first << endl;
}
}
}

Is there any other better way can handle this treversal better?

Thanks
Sam

You can use the std::copy function from the standard library, as
demonstrated in several sources around the net, like this one:

http://www.devx.com/getHelpOn/10MinuteSolution/20410/1954?pf=true

under the header "Dumping a Container". For general traversals, you
might also want to check out std::for_each.