QMap::contains() not returning expected value

Question

I have a class that contains a QMap object:

QMap<QString, Connection*> users;

Now, in the following function Foo(), the if clause always returns false but when I iterate through the map, the compared QString, i.e., str1 is present in the keys.

void Foo(QString& str1, QString& str2)
{    
    if(users.contains(str1))
        users[str1]->doStuff(str2);
    else
    {
        for(QMap<QString, Connection>::iterator iter = users.begin(); 
                           iter!= users.end();iter++)
            qDebug()<<iter.key();
    }
}

Am I doing something wrong? Why doesn't contains() return true ?

Is there a typo in your question? You say that `str2` is present in the keys, but you're checking if `users` contains `str1`. — Steve S, Oct 21 '10 at 17:21

score 5 · Accepted Answer · edited Sep 24 '14 at 15:19

5

With unicode, two strings may be rendered the same but actually be different. Assuming that's the case you'll want to normalize the strings first:

str = str.normalize(QString::NormalizationForm_D);
if (users.contains(str))
    // do something useful

Of course, you'll need to normalize the string before you put it in your users map as well.

edited Sep 24 '14 at 15:19

azalea

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answered Oct 21 '10 at 17:32

Kaleb Pederson

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Even after normalizing the QString before storing in the QMap and before checking, contains() returns false only. – Saurabh Manchanda Oct 21 '10 at 17:46
Please show us in what way the strings are different. For example, `qDebug() << str.toUtf8()` should show us the actual bytes that create the string. – Kaleb Pederson Oct 21 '10 at 17:55
After cleaning the project and rebuilding, it worked. Thanks. – Saurabh Manchanda Oct 21 '10 at 17:56

QMap::contains() not returning expected value

1 Answers1