Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
611 views
in Technique[技术] by (71.8m points)

stl - Iterate keys in a C++ map

Is there a way to iterate over the keys, not the pairs of a C++ map?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

map is associative container. Hence, iterator is a pair of key,val. IF you need only keys, you can ignore the value part from the pair.

for(std::map<Key,Val>::iterator iter = myMap.begin(); iter != myMap.end(); ++iter)
{
Key k =  iter->first;
//ignore value
//Value v = iter->second;
}

EDIT:: In case you want to expose only the keys to outside then you can convert the map to vector or keys and expose.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

2.1m questions

2.1m answers

60 comments

57.0k users

...