[Qt-interest] Why do I get a "" key in my map?

[Andreas Pakulat]

On 08.06.10 08:52:12, Jason H wrote:
> void DlgEditVSN::setVSNs(QMap<QString, QString> VSNs)
> {
>     _VSNs = VSNs;
>     while(ui.cmbSiteNames->count())
>         ui.cmbSiteNames->removeItem(0);
> 
>     foreach(const QString& site, _VSNs.keys())
>     {
>         ui.cmbSiteNames->addItem(site, _VSNs.value(site)); // THIS LINE MAKES A NULL KEY IN VSNs

There's a bit of context missing, in particular you didn't quite formulate
a clear question. But QMap::value is documented to insert a
default-constructed value if there is no one yet in the map for the given
key. So its expected that value inserts into _VSNs if site doesn't exist in
it yet.

Andreas

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