I'd like to use the find() method, to catch a particular element of my std::map()
Now the return value is either the element I was looking for, or it it points to the end of the map if the element hasn't been found (C.f.: http://www.cplusplus.com/reference/map/map/find/ ).
So I'm using these two information whether to decide if an element is in the map or not. But what happens if the element is already inside but at the very end ? My if-query would then decide that it's not existing and therefor my program will be made up.
Am I getting this routine right, and if, how to prevent it ?
Thanks for your support
The last element in any container is not the same as the containers
end
iterator. Theend
iterator is actually one step beyond the last element in the container.That means you can rest easily, and use
find
without worries. If the element you look for is the last element, you will get what you search for.You can actually use
if(!map.count(elem))
to check whetherelem
is present in the map,count()
returns 0 ifelem
is not present in the map whilefind()
returns an iterator which has to been compared to the end iterator, i.e.,if(map.find(elem) != map.end())
.