how to get only folder count in a directory

[mrjj]

@ARASHz4
Ok, so only first level of subdirectories.
Try with QDir::entryList() then as @JNBarchan suggests.

[JonB]

@ARASHz4
Or, if you do want to use QDirIterator, you need to use the QDirIterator::QDirIterator(const QString &path, QDir::Filters filters, IteratorFlags flags = NoIteratorFlags) overload and set filters (not flags) as per what I wrote earlier.

[ARASHz4]

@JNBarchan i try :

QDir(FolderAddress).entryList(QDir::AllDirs | QDir::NoDotAndDotDot).count()

this return folder count in a directory

thank you

[JonB]

@ARASHz4
That's right, and just what I suggested :(

Note that this simplest code builds a list of all directories in memory and then counts them. I think that's fine for a reasonable number of sub-directories. However, if you have like 1,000+ that's where QDirIterator approach would be more efficient (memory-wise) by not building a list, but requires a touch more lines of code, if you ever feel like it.

[t3685]

@JNBarchan

You can call http://doc.qt.io/qt-5/qdiriterator.html#fileInfo and http://doc.qt.io/qt-5/qfileinfo.html#isDir to only count directories.

[JonB]

@t3685
But that is likely to be "inefficient", since you have to visit every entry (files as well as directories) in your code and then test whether it's a directory. That's the whole point of using the QDir::Filters approach, which (presumably) allows the Qt code to use whatever native function might be available to only pick out directories in the first place....

[ARASHz4]

@JNBarchan can you show me a example with QDirIterator for get folder count

[ARASHz4]

@JNBarchan I think this code no builds a list of all directories in memory

QDir folder (FolderAddress);
folder.setFilter(QDir::AllDirs | QDir::NoDotAndDotDot);
int folderCount = folder.count();

[JonB]

@ARASHz4
From @mrjj 's earlier suggestion, just modify to:

QDirIterator it("/etc", QDir::AllDirs | QDir::NoDotAndDotDot);
while (it.hasNext()) {
    qDebug() << it.next();

and count them. This way does not build a list in memory.

[JonB]

@ARASHz4 said in how to get only folder count in a directory:

@JNBarchan I think this code no builds a list of all directories in memory

QDir folder (FolderAddress);
folder.setFilter(QDir::AllDirs | QDir::NoDotAndDotDot);
int folderCount = folder.count();

I believe that way does build a complete list, internally, and then evaluates the count() on the list. Need to use QDirIterator instead of QDir if want be sure no list built.