QMultiHash Iterator order for values of same key

Question

Consider the following code:

QMultiHash<int, Tag*>::iterator i = th.begin(); while(i != th.end()) {
    int key = i.key();
    Value* val = i.value();
    if(key == lastkey) {
        // Do something
    }
    else {
        // Do Something else
    }
}

Is the assumption that the entries with the same keys are returned consecutively by the iterator?

Thank you in advance.

Answer 1

Is the assumption that the entries with the same keys are returned consecutively by the iterator?

Yes. See the code below demonstrating this.

main.cpp

#include <QMultiHash>
#include <QString>
#include <QDebug>

int main()
{
    QMultiHash<QString, int> stringIntMultiHash;
    stringIntMultiHash.insert("foo", 2);
    stringIntMultiHash.insert("bar", 5);
    stringIntMultiHash.insert("oo", 0);
    stringIntMultiHash.insert("bar", 132);
    stringIntMultiHash.insert("baz", 2131);
    stringIntMultiHash.insert("foo", 10);
    stringIntMultiHash.insert("stuff", 20);
    stringIntMultiHash.insert("baz", 30);

    for (QMultiHash<QString, int>::iterator i = stringIntMultiHash.begin(); i != stringIntMultiHash.end(); ++i)
        qDebug() << "Key:" << i.key() << "Value:" << i.value();
}

Output

g++ -Wall -fPIC -lQt5Core -I/usr/include/qt/QtCore -I/usr/include/qt main.cpp && ./a.out

Key: "bar" Value: 132 
Key: "bar" Value: 5 
Key: "stuff" Value: 20 
Key: "foo" Value: 10 
Key: "foo" Value: 2 
Key: "baz" Value: 30 
Key: "baz" Value: 2131 
Key: "oo" Value: 0