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I'm using Qt 4.5 and im working with a QList<QStringList> which is a list of string list.
Now I want to replace one string inside one stringList but with it seems unusual to type. I have found the following way of doing it and was wondering if it is ok:
QList <QStringList> pDataList;
pDataList[listIndex].replace(QStringIndex, newString);
Now, I'm not worried about the syntax, but I want to know if pDataList's pointers is adjascent in memory so that it is okay to use []. Is there another way to do it?
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Iterating Over the Strings To iterate over a list, you can either use index positions or QList's Java-style and STL-style iterator types: Indexing: for (int i = 0; i < fonts. size(); ++i) cout << fonts.at(i).
You may write them, or you can just write copying function on your own -- reversing a list is a nice excersize. Or you can note that QList is actually an array, what makes writing such a function trivial. Or you can convert the list to std::list, and use rbegin and rend. Choose whatever you like.
QList<T> is one of Qt's generic container classes. It stores items in a list that provides fast index-based access and index-based insertions and removals.
The issue of pDataList's elements being adjacent in memory is not related to the question of whether it is ok to use operator[].
In general, QList<> does not guarantee that its elements are adjacent in memory, but it does overload operator[] to give you the element you're looking for nonetheless.
The only thing you need to worry about when doing something like this is to make sure that (pDataList.size() < listIndex). otherwise, you'll be indexing elements not in the list, triggering an exception in debug or undefined behavior in release.
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