QStringList list;
QMap<QString, QString> parse_list;

-----------------------------

for (int j = 0; j < list.size(); j++){
	qDebug() << info_list[i];

	QMapIterator<QString, QString> i(parse_list);
	while (i.hasNext()){
		i.next();
	}
}

все зачипенно

----------------------------
for (int j = 0; j < list.size(); j++){

	QMapIterator<QString, QString> i(parse_list);
	while (i.hasNext()){
		i.next();
	}
	qDebug() << info_list[i];
}

widget.cpp: В функции-члене «void Widget::test(QString)»:
widget.cpp:505:28: ошибка: no match for «operator[]» in «info_list[i]»
widget.cpp:505:28: замечание: candidates are:
In file included from /usr/include/qt4/QtCore/qhash.h:48:0,
                 from /usr/include/qt4/QtCore/qcache.h:45,
                 from /usr/include/qt4/QtCore/QtCore:7,
                 from /usr/include/qt4/QtNetwork/QtNetwork:3,
                 from widget.h:4,
                 from widget.cpp:1:
/usr/include/qt4/QtCore/qlist.h:472:17: замечание: const T& QList<T>::operator[](int) const [with T = wearCarPartInfo]
/usr/include/qt4/QtCore/qlist.h:472:17: замечание:   no known conversion for argument 1 from «QMapIterator<QString, QString>» to «int»
/usr/include/qt4/QtCore/qlist.h:476:11: замечание: T& QList<T>::operator[](int) [with T = wearCarPartInfo]
/usr/include/qt4/QtCore/qlist.h:476:11: замечание:   no known conversion for argument 1 from «QMapIterator<QString, QString>» to «int»