Hi,
If you always use replace, there won’t be double keys.
This is depending on your implementation.
Other option:
Use the find() method on the class.
Then use an iterator on the results to assign the new value.
But if I read your mail, you suggest that you always replace ALL values with
the same key.
(Then I would like to know why you have double keys at all?!)
So then I would just use replace. Then the key will occur only once.
I’m working with assumptions, so that’s why I ‘offer’ two solutions.
Kind regards,
Danny
Van: development-bounces+d.koppel=skf-rif...@qt-project.org
[mailto:development-bounces+d.koppel=skf-rif...@qt-project.org] Namens
pengliang(??)
Verzonden: donderdag 7 maart 2013 10:59
Aan: Danny Koppel; development@qt-project.org
Onderwerp: [Development] 答复: [Qt-interest] QMultiHash
Hi
1.
QmultiHash replace() is only replace first item, I want to replace all values
when key is matched.
Qt docs : if there are multiple items with the key, the most recently inserted
item's value is replaced with value.
Who have a better method?
2. so I need to use Qmaplong,Qstring,
I found qt source code below, so I think Qhashlong,Qstring is ordered by
long, am I right?
inline uint qHash(long key) { return qHash(ulong(key)); }
template class T inline uint qHash(const T *key)
{
return qHash(reinterpret_castquintptr(key));
}
Thanks
Ken
发件人: Danny Koppel [mailto:d.kop...@skf-rif.nl]
发送时间: 2013年3月7日 17:39
收件人: 'pengliang(??)';
development@qt-project.orgmailto:development@qt-project.org
主题: RE: [Development] [Qt-interest] QMultiHash
Hello,
I don’t know if I understand you correctly but the QMultiHash class has the
function replace which does what you describe.
It replaces the value of an existing key or creates a new one if the key
doesn’t exist yet.
About point 2: the documentation describes it as follows: “When iterating over
a QMapqthelp://org.qt-project.qtcore.501/qtcore/qmap.html, the items are
always sorted by key. With QHash, the items are arbitrarily ordered.”.
Kind regards,
Danny
Van:
development-bounces+d.koppel=skf-rif...@qt-project.orgmailto:development-bounces+d.koppel=skf-rif...@qt-project.org
[mailto:development-bounces+d.koppel=skf-rif...@qt-project.org] Namens
pengliang(??)
Verzonden: donderdag 7 maart 2013 10:25
Aan: development@qt-project.orgmailto:development@qt-project.org
Onderwerp: [Development] [Qt-interest] QMultiHash
Hi All
QMultiHashQstring,inthh;
I need to find some key and change their values.
I found If I use QmutableHashIteratorQstring,intit , its
bool
findNextqmutablehashiterator.html#findNext ( const T value )
Its parameter is a value, not a key.
So I need to :
While(it.hasNext())
{
It.next();
If(it.key() == ikey)
{
It.setValue(ivalue);
}
}
I must to check every item? Who have a better method?
2. Qhash:
Some books said Qhash is unorderred?
But I test it.
QhashQstring,inthh;
I insert some string, and loop the hash by QhashIterator, I found the string is
orderred.
And I test it Qhashint,Qstring, and print key, and found they still orderred.
Why books said it is unorderred?
Thanks
ken
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